Compositions comprising at least one oxonol dye and at least one metal complex

ABSTRACT

The present invention relates to compositions comprising at least one oxonol dye and at least one metal complex of formula (I-1) or (I-2), to recording media comprising the compositions and to use of the compositions in the production of optical recording media, colour filters and printing inks, wherein the substituents are as defined in the description. Use of the metal complexes of formula (I) results, surprisingly, in a comparatively weak tendency of the oxonol dyes to aggregate in the solid state so that the absorption curve remains advantageously narrow even in the solid state, as a result of which recording media having high reflectivity as well as high sensitivity and good playback characteristics in the desired spectral range are made available.

The present invention relates to compositions comprising at least oneoxonol dye and at least one metal complex of formula (I-1) or (I-2), torecording media comprising the compositions and to use of thecompositions in the production of optical recording media, colourfilters and printing inks. Use of the metal complexes of formula (I)results, surprisingly, in a comparatively weak tendency of the oxonoldyes to aggregate in the solid state so that the absorption curveremains advantageously narrow even in the solid state, as a result ofwhich recording media having high reflectivity as well as highsensitivity and good playback characteristics in the desired spectralregion are made available.

The field of the invention is the optical storage of information bymeans of write-once storage media, the information markings (informationpits) being distinguished by means of the differing optical propertiesof a colorant at written and unwritten locations. This technology isusually termed “WORM” (for example, “CD-R” or “DVD-R”).

Compact discs that are writable at a wavelength of from 770 to 830 nmare known from “Optical Data Storage 1989”, Technical Digest Series,Vol. 1, 45 (1989). They are read with reduced read-out performance.According to the Orange Book Standard, the medium must have a basicreflectivity of 65% or more at the recording wavelength. As recordingmedia there may be used, for example, cyanine dyes (JP-58/125246),phthalocyanines (EP-A-676 751, EP-A-712 904), azo dyes (U.S. Pat. No.5,441,844), double salts (U.S. Pat. No. 4,626,496), azo metal complexes(U.S. Pat. No. 5,272,047, U.S. Pat. No. 5,294,471, EP-A-649 133,EP-A-649 880) or mixtures thereof (EP-A-649 884) or oxonol dyes (U.S.Pat. No. 6,225,024, EP-A-0 833 314, U.S. Pat. No. 4,968,593). Inaddition to the dyes, the recording layer may comprise stabilisers suchas, for example, singlet oxygen quenchers, fluorescence quenchers andfree radical capture agents.

JP 60-0044390 A accordingly relates to an optical recording mediumcomprising a substrate and a recording medium, the recording layercomprising a cyanine dye, or a cyanine dye and a binder, and, inaddition, at least one compound of formula

wherein R³⁰¹, R³⁰², R³⁰³ and R³⁰⁴ are each a hydrogen atom or amonovalent group, or pairs of R³⁰¹ and R³⁰², R³⁰² and R³⁰³, and R³⁰³ andR³⁰⁴ may be connected to one another to form a six-membered ring, R³⁰⁵and R³⁰⁸ are each a hydrogen atom or a substituted or unsubstitutedalkyl or aryl radical, R³⁰⁶ is a hydrogen atom, a hydroxy group or asubstituted or unsubstituted alkyl or aryl radical, R³⁰⁷ is asubstituted or unsubstituted alkyl or aryl radical, Z′ is a group ofnon-metal atoms necessary for the formation of a five- or six-memberedring, and M′ is a transition metal atom.

JP 09-164767 A furthermore describes a recording material comprising arecording layer comprising a phthalocyanine compound and a stabiliser ofthe following formula

wherein A′ is a phenyl or naphthalene ring which is substituted by asulfonic acid group, and M″ is a transition metal atom.

The aim of the invention was to make available an optical recordingmedium wherein the recording layer has a high storage capacity togetherwith outstanding other properties. It should be possible for therecording medium to be both written and read at high speed, with as fewerrors as possible, at the same wavelength in the range from 600 to 700nm (preferably from 630 to 690 nm), or at less than 450 nm.

It has now been found, surprisingly, that the following advantages areobtained by combining oxonol dyes with specific metal complexes:

-   -   disaggregation of the dyes, resulting in an ideal absorption        curve, which is not the case when the dyes known from EP-A-833        314 are used on their own;    -   improvement of light-stability, and    -   improved solubility of such compositions in polar solvents.

The invention accordingly relates to compositions comprising at leastone oxonol dye and at least one, that is to say from 1 to 5, preferablyfrom 1 to 3, metal complex of the following formula

Me is a transition metal of Sub-Group 7, 8, 9, 10, 11 or 12, preferably9, 10 or 11, D¹ and D² are each independently of the other a carbocyclicor heterocyclic ring or ring system, which may be unsubstituted orsubstituted by one or more groups R⁵ and R⁶, R⁵ and R⁶ being a halogenatom, such as fluorine, chlorine or bromine, an amino group, analkylamino group, a dialkylamino group, a nitro group, a cyano group, ahydroxy group, an unsubstituted or substituted alkyl radical, anunsubstituted or substituted hydroxyalkyl radical, an unsubstituted orsubstituted alkoxy radical, an alkyl radical which is interrupted one ormore times by —O— or by —S— and which may be unsubstituted orsubstituted, an acyl radical, a phenyl group, an ester group, such as aphosphonic acid, phosphoric acid or carboxylic acid ester group, acarboxamide group, a sulfamide group, an ammonium group, a carboxylicacid, sulfonic acid, phosphonic acid or phosphoric acid group or a saltthereof, R¹ and R⁴ are each independently of the other a hydrogen atomor an unsubstituted or substituted alkyl radical, aryl radical oraralkyl radical,

-   R², R²′, R³ and R³′ are each independently of the others a hydrogen    atom, a cyano group, an unsubstituted or substituted alkyl radical,    alkoxy radical, aryl radical or aralkyl radical, an ester group, a    carboxamide group, a sulfamide group, a trialkylammonium group, a    carboxylic acid, sulfonic acid, phosphonic acid or phosphoric acid    group or a salt thereof, or R² and R³ together, or R²′ and R³′    together, form a double bond, a cycloalkyl ring or a heterocyclic    ring, or-   R², R²′, R³ and R³′ together form an aromatic carbocyclic or    heterocyclic ring,-   R² and R²′ together, and/or R³ and R³′ together, form, each pair    independently of the other, a carbonyl group or a thiocarbonyl    group,-   R⁷, R⁷′, R⁸ and R⁸′ are each independently of the others a hydrogen    atom or an unsubstituted or substituted alkyl radical, aryl radical    or aralkyl radical, or-   R⁷ and R⁷′ together, and/or R⁸ and R⁸′ together, form, each pair    independently of the other, a carbonyl group or a thiocarbonyl    group,-   to optical recording media comprising a substrate and at least one    recording layer wherein the recording layer comprises the    above-mentioned composition, and to use of the above-mentioned    composition in the production of optical recording media, colour    filters (optical filters) and printing inks.

The use of the metal complexes of formula (I) in combination with oxonoldyes results, surprisingly, in a comparatively weak tendency of theoxonol dyes to aggregate in the solid state so that the absorption curveremains advantageously narrow even in the solid state, as a result ofwhich recording media having high reflectivity as well as highsensitivity and good playback characteristics in the desired spectralranged are made available.

The metal complex used generally has the following formula

Me is a transition metal of Sub-Group 7, 8, 9, 10, 11 or 12, preferably9, 10 or 11, D¹ and D² are each independently of the other a carbocyclicor heterocyclic ring or ring system, which may be unsubstituted orsubstituted by one or more groups R⁵ and R⁶, R⁵ and R⁶ being a halogenatom, such as fluorine, chlorine or bromine, an amino group, analkylamino group, a dialkylamino group, a nitro group, a cyano group, ahydroxy group, an unsubstituted or substituted alkyl radical, anunsubstituted or substituted hydroxyalkyl radical, an unsubstituted orsubstituted alkoxy radical, an alkyl radical which is interrupted one ormore times by —O— or by —S— and which may be unsubstituted orsubstituted, an acyl radical, a phenyl group, an ester group, such as aphosphonic acid, phosphoric acid or carboxylic acid ester group, acarboxamide group, a sulfamide group, an ammonium group, a carboxylicacid, sulfonic acid, phosphonic acid or phosphoric acid group or a saltthereof, R¹ and R⁴ are each independently of the other a hydrogen atomor an unsubstituted or substituted alkyl radical, aryl radical oraralkyl radical,

-   R², R²′, R³ and R³′ are each independently of the others a hydrogen    atom, a cyano group, an unsubstituted or substituted alkyl radical,    alkoxy radical, aryl radical or aralkyl radical, an ester group, a    carboxamide group, a sulfamide group, a trialkylammonium group, a    carboxylic acid, sulfonic acid, phosphonic acid or phosphoric acid    group or a salt thereof, or R² and R³ together, or R²′ and    R^(3′ together, form a double bond, a cycloalkyl ring or a heterocyclic ring, or)-   R², R²′, R³ and R³′ together form an aromatic carbocyclic or    heterocyclic ring,-   R² and R²′ together, and/or R³ and R³′ together, form, each pair    independently of the other, a carbonyl group or a thiocarbonyl    group,-   R⁷, R⁷′, R⁸ and R⁸′ are each independently of the other a hydrogen    atom or an unsubstituted or substituted alkyl radical, aryl radical    or aralkyl radical, or-   R⁷ and R⁷′ together, and/or R⁸ and R⁸′ together, form, each pair    independently of the other, a carbonyl group or a thiocarbonyl    group.

Examples of cations that form a salt with a carboxylic acid, sulfonicacid, phosphonic acid or phosphoric acid group are metal cations such asa sodium, potassium, lithium, calcium, iron and copper ion, a metalcomplex cation or an ammonium cation.

In accordance with the invention, an alkyl radical is understood to be astraight-chain or branched C₁₋₂₄alkyl radical, preferably C₁₋₈alkylradical, which may be unsubstituted or substituted, such as, forexample, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl,isobutyl, tert-butyl, cyclobutyl, n-pentyl, 2-pentyl, 3-pentyl,2,2-dimethylpropyl, hexyl, heptyl, 2,4,4-trimethylpentyl, 2-ethylhexylor octyl, ethoxycarbonylethyl, cyanoethyl, diethylaminoethyl,chloroethyl, acetoxyethyl and trifluoromethyl.

In accordance with the invention, an alkoxy radical is understood to bea straight-chain or branched C₁₋₂₄alkoxy radical, that is to sayO—C₁₁₋₂₄alkyl, preferably O—C₁₋₈lalkyl, such as, for example, methoxy,ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy,tert-butoxy, n-pentyloxy, 2-pentyloxy, 3-pentyloxy, 2,2-dimethylpropoxy,n-hexyloxy, n-heptyloxy, n-octyloxy, 1,1,3,3-tetramethylbutoxy or2-ethylhexyloxy.

In accordance with the invention, an acyl radical or alkylcarbonylradical is understood to be a C₁₋₂₄alkylcarbonyl radical, preferablyC₁₋₈alkylcarbonyl radical, which may be unsubstituted or substituted,such as, for example, acetyl, propionyl, butanoyl or chloroacetyl. Inaccordance with the invention, an aromatic carbocyclic ring or an arylradical is understood to be a C₆₋₂₄aryl radical, preferably C₆₋₁₂arylradical, which may be unsubstituted or substituted, such as, forexample, phenyl, 4-methylphenyl, 4-methoxyphenyl, naphthyl, biphenylyl,2-fluorenyl, phenanthryl, anthryl or terphenylyl.

In accordance with the invention, an aralkyl radical is understood to bea C₇₋₂₄aralkyl radical, preferably C₇₋₁₂aralkyl radical, which may beunsubstituted or substituted, such as, for example, benzyl,2-benzyl-2-propyl, β-phenethyl, 9-fluorenyl, α,α-dimethylbenzyl,ω-phenylbutyl, ω-phenyl-octyl, ω-phenyl-dodecyl or3-methyl-5-(1′,1′,3′,3′-tetramethyl-butyl)-benzyl. In accordance withthe invention, an alkyl radical which is interrupted one or more timesby —O— or by —S— is understood to be a straight-chain or branchedC₂-C₂₄alkyl radical, preferably C₂-C₈alkyl radical, which may beinterrupted one or more times by —O— or by —S—, for example one, two orthree times by —O— and/or by —S—, resulting in structural units such as,for example, —(CH₂)₂OCH₃, —(CH₂CH₂O)₂CH₂CH₃, —CH₂—O—CH₃,—CH₂CH₂—O—CH₂CH₃, —CH₂CH₂CH₂—O—CH(CH₃)₂, —[CH₂CH₂O]_(Y1)—CH₃ whereinY1=1-3, —CH₂—CH(CH₃)—O—CH₂—CH₂CH₃ and —CH₂—CH(CH₃)—O—CH₂—CH₃.

In accordance with the present invention, the expression “ester group”encompasses carboxylic acid esters —C(O)OR¹⁰¹, phosphonic acid esters—P(O)OR¹⁰²OR¹⁰³ and phosphoric acid esters —OP(O)OR¹⁰²OR¹⁰³, whereinR¹⁰¹ is an unsubstituted or substituted alkyl, aryl or aralkyl radicalor is an alkyl radical which is interrupted one or more times by —O— orby —S— and which is unsubstituted or substituted by a hydroxy group,R¹⁰² and R¹⁰³ are a hydrogen atom, an unsubstituted or substitutedalkyl, aryl or aralkyl radical or are an alkyl radical which isinterrupted one or more times by —O— or by —S— and which isunsubstituted or substituted by a hydroxy group, such as, for example,—C(O)OCH₂CH₂OCH₂CH₂OCH(CH₃)₂ and —C(O)OCH₂CH₂OCH₂CH₂OH.

The expression “sulfamide group” indicates a group —SO₂NR¹⁰²R¹⁰³ whereinR¹⁰² and R¹⁰³ are as defined above.

An amino group, alkylamino group or dialkylamino group is understood tobe a group —NR¹⁰⁴R¹⁰⁵ wherein R¹⁰⁴ and R¹⁰⁵ are each independently ofthe other a hydrogen atom, a C₁₋₂₄alkyl radical, a C₁₋₂₄alkylcarbonylradical or a C₁₋₂₄alkylcarbonyl radical substituted by halogen, aC₁₋₂₄alkoxycarbonyl radical, a C₆₋₂₄aryl radical, a C₇₋₂₄aralkyl radicalor a C₆₋₂₄aryl- or C₇₋₂₄aralkyl-carbonyl radical, or R¹⁰⁴ and R¹⁰⁵together form a five- to seven-membered heterocyclic ring. Examples areamino, methylamino, ethylamino, dimethylamino, diethylamino,phenylamino, methoxycarbonylamino, acetylamino, ethylcarbonylamino,cyclohexylcarbonylamino, benzoylamino or chloroacetylamino, morpholino,piperidino or pyrrolidino.

A C₁₋₂₄alkoxycarbonyl radical is understood to be a straight-chain orbranched C(O)O-C₁₋₂₄alkyl radical, preferably C(O)O—C₁₋₈alkyl radical,such as, for example, methoxy-, ethoxy-, n-propoxy-, isopropoxy-,n-butoxy-, sec-butoxy-, isobutoxy- or tert-butoxy-carbonyl. Examples ofa C₆₋₂₄aryl- or C₇₋₂₄aralkyl-carbonyl radical are a phenylcarbonyl groupand a benzylcarbonyl group, respectively.

In accordance with the invention, an “ammonium group” is understood tobe a group —N¹⁰⁶R¹⁰⁷R¹⁰⁸ wherein R¹⁰⁶, R¹⁰⁷ and R¹⁰⁸ are a hydrogen atomor an unsubstituted or substituted alkyl, aryl or aralkyl radical.

Examples of an (aromatic) heterocyclic ring (or ring system) areheterocycles having from 3 to 12 carbon atoms, for example 2-thienyl,2-furyl, 1-pyrazolyl, 2-pyridyl, 2-thiazolyl, 2-oxazolyl, 2-imidazolyl,isothiazolyl, triazolyl or any other ring system consisting ofthiophene, furan, pyrazole, thiazole, oxazole, imidazole, isothiazole,thiadiazole, triazole, pyridine or benzene rings unsubstituted orsubstituted by from 1 to 6 ethyl, methyl, ethylene and/or methylenesubstituents.

Examples of a saturated heterocyclic ring are heterocycloalkanes havingfrom 4 to 6 carbon atoms which have one or two hetero atom(s) selectedfrom nitrogen, oxygen and sulfur, for example tetrahydrofuran,tetrahydropyran, 1,4-dioxane, thiolane, piperidine, γ-butyrolactone,5-aminopentanoic acid lactam or pyrrolidine.

Examples of a carbocyclic ring or ring system are cycloalkyls havingfrom 5 to 12 carbon atoms, for example cyclopentane, cyclohexane orcycloheptane, or aromatic rings having from 6 to 24 carbon atoms, suchas phenyl or naphthyl.

The definitions given hereinbefore for the radicals in formulae (I-1)and (I-2) apply to the entire invention, unless otherwise specified.

Me is preferably a transition metal of Sub-Group 9, 10 or 11, especiallyCu, nickel or cobalt.

R¹ and R⁴ preferably are a hydrogen atom or a C₁₋₄alkyl radical,especially a methyl or ethyl group.

R², R²′, R³ and R³′ are preferably a hydrogen atom, a C₁₋₂₄alkyl radicalwhich is unsubstituted or substituted by a phosphoric acid ester group,for example (PhO)(HO)P(O)O—; a phosphoric acid group or phosphoric acidester group; or a phenyl group which is unsubstituted or substituted bya sulfonic acid group, or R² and R³ together, or R²′ and R³′ together,preferably form a double bond or a cycloalkyl ring or heterocyclic ring

or R², R²′, R³ and R³′ together preferably form one of the followingaromatic heterocyclic rings

(N and Me are added for clarity reasons; the formed ring is highlightedin boldface).

R⁷, R⁷′, R⁸ and R⁸′ are preferably a hydrogen atom or an unsubstitutedor substituted C₁₋₈alkyl radical, a phenyl group or a benzyl group, orR⁷ and R⁷′ together, and/or R⁸ and R⁸′ together, form a carbonyl groupor a thiocarbonyl group.

Preferred groups D¹ and D² have the following structures:

-   R⁵¹, R⁵², R⁵³ R⁵⁴=H,-   R⁵¹, R⁵³, R⁵⁴═H, R⁵²═CH₃, OH, C₁₈H₃₇O, Br, Cl,    2,4,4-trimethylpentyl-1-oxymethyl or SO₃H,-   R⁵¹, R⁵², R⁵⁴═H, R⁵³═CH₃, OH, C₄H₉O, C₈H₁₇O, C₁₂H₂₅O,    3,5,5-trimethylhexyloxy, 2-octyldodecyloxy, R^(x)O-[CH₂CH₂—O—]_(x)    wherein R^(x) is a methyl group and x is 1, or R^(x) is an ethyl    group and x is 2, or R^(x) is a butyl group and x is 2, or R^(x) is    a methyl group and x is 3,-   (CH₃CH₂O)₂P(═O)O— or H₂NC(═O)CH₂O—,-   R⁵¹, R⁵² R⁵³═H, R⁵⁴═OCH₃, CH₃ or OH,-   R⁵¹, R⁵⁴═H and R⁵²═SO₃H, R⁵³═CH₃,-   R⁵¹, R⁵³═H and R⁵², R⁵⁴═Cl, CH₃, OH or Br,-   R⁵¹, R⁵³═H and R⁵²=t-Bu, R⁵⁴═CH₃,-   R⁵¹ R⁵³═H and R⁵²═Cl, R⁵⁴═SO₃H,-   R⁵¹, R⁵³=H and R⁵²═Br, R⁵⁴═SO₃H,-   R⁵¹, R⁵³═H and R⁵²═Cl, R⁵⁴═OCH₃ or-   R⁵¹, R⁵³═H and R⁵²═SO₃H, R⁵⁴═OCH₃ or CH₃, the preferred meanings of    R⁶¹, R⁶², R⁶³ and R₆₄ being the same;    wherein-   R⁵⁵═H, R⁵⁶═H, CO₂H, CO₂CH₃ or C(═O)NHPh; R⁵⁵═Br, R⁵⁶═CO₂H; or    R⁵⁵=SO₃H, R⁵⁶═H.

Preference is further given to R² and R³ together, or R²′ and R³′together, forming a double bond and to R²′ and R³′, or R² and R³, as thecase may be, being cyano groups. Such compounds of formula (I) arecoloured and make a contribution to the refractive index. The presentinvention accordingly relates also to the use, in the optical storage ofinformation, of a metal complex of formula (I-1) wherein Me, D¹ and D²,R⁵ and R⁶, R¹ and R⁴ are as defined hereinbefore, R² and R³ form adouble bond and R²′ and R³′ are cyano groups.

The metal complex is preferably a compound of formula

-   Me is Cu, Ni, Co or Zn, especially Cu,-   R⁵¹, R⁵², R⁵³, R⁵⁴, R⁶¹, R⁶², R⁶³ and R⁶⁴ are a hydrogen atom, a    halogen atom, such as fluorine, chlorine or bromine, an amino group,    an alkylamino group, a dialkylamino group, a nitro group, a cyano    group, a hydroxy group, an alkyl radical, a hydroxyalkyl radical, an    alkoxy radical, an alkyl radical which is interrupted one or more    times by —O— or by —S—, an acyl radical, a phenyl group, an ester    group, such as a phosphonic acid, phosphoric acid or carboxylic acid    ester group, a carboxamide group, a sulfamide group, a di- or    tri-alkylammonium group, a carboxylic acid or sulfonic acid or    phosphoric acid group or a salt thereof, or-   R⁵¹ and R⁵² together, and/or R⁶¹ and R⁶² together, form an    unsubstituted or substituted phenyl ring,-   R¹ and R⁴ are each independently of the other a hydrogen atom or an    unsubstituted or substituted alkyl radical, aryl radical or aralkyl    radical,-   R², R²′, R³ and R³′ are a hydrogen atom, a cyano group or a    C₁₋₈alkyl radical, or R² and R³ together, and/or R²′ and R³′    together, form a double bond, an unsubstituted or substituted    cycloalkyl ring containing from 5 to 7 carbon atoms, especially a    cyclohexane ring, or an unsubstituted or substituted aromatic ring    containing from 5 to 7 carbon atoms, especially a phenyl ring,-   R⁷, R⁷′, R⁸ and R⁸′ are each independently of the others a hydrogen    atom or an unsubstituted or substituted C₁₋₈alkyl radical, a phenyl    group or a benzyl group, or-   R⁷ and R⁷′ together, and/or R⁸ and R⁸′ together, form, each    independently of the others, a carbonyl group or a thiocarbonyl    group.

The metal complex is especially a compound of formula

-   Me is Cu, Ni or Co; R⁵¹, R⁵², R⁵³, R⁵⁴, R⁶¹, R⁶², R⁶³ and R⁶⁴ are a    hydrogen atom, a chlorine atom, a bromine atom, a hydroxy group, a    C₁₋₈alkyl radical which may be unsubstituted or substituted by a di-    or tri-alkylammonium group, a C₁₋₁₆alkoxy radical which may be    unsubstituted or substituted by a di- or tri-alkylammonium group, a    C₁₋₈alkyl radical which is interrupted one or more times by —O— or    by —S— and which may be unsubstituted or substituted by a di- or    tri-alkylammonium group; an ester group, such as a carboxylic acid    ester —C(O)OR¹⁰¹, phosphonic acid ester —P(O)OR¹⁰²R¹⁰³ or phosphoric    acid ester —OP(O)OR¹⁰²OR¹⁰³, wherein R¹⁰¹ is an unsubstituted or    substituted C₁₋₁₂alkyl, C₆₋₁₂aryl or C₇₋₁₂aralkyl radical, or a    C₁-C₁₂alkyl radical which is interrupted one or more times by —O— or    by —S— and which is unsubstituted or substituted by a hydroxy group,    such as, for example, —C(O)OCH₂CH₂OCH₂CH₂OCH(CH₃)₂ or    —C(O)OCH₂CH₂OCH₂CH₂OH, R¹⁰² and R¹⁰³ are a hydrogen atom, an    unsubstituted or substituted C₁₋₁₂alkyl, C₆₋₁₂aryl or C₇₋₁₂aralkyl    radical or a C₁₋₁₂alkyl radical which is interrupted one or more    times by —O— or by —S— and which is unsubsttuted or substituted by a    hydroxy group, such as, for example, —C(O)OCH₂CH₂OCH₂CH₂OCH(CH₃)₂ or    —C(O)OCH₂CH₂OCH₂CH₂OH; a carboxamide group, a sulfamide group or a    di- or tri-alkylammonium group; R¹ and R⁴ are each independently of    the other a hydrogen atom or an alkyl radical; R², R²′, R³ and R³′    are a hydrogen atom, a cyano group or a C₁₋₈alkyl radical or pairs    of the radicals R² and R²′ together and R³ and R³′ together form a    double bond or a cyclohexane ring, at least one of the radicals R⁵¹,    R⁵², R⁵³, R⁵⁴, R⁶¹, R⁶², R⁶³ and R⁶⁴ being a di- or    tri-alkylammonium group or being substituted by a di- or    tri-alkylammonium group;-   R⁷, R⁷′, R⁸ and R⁸′ are each independently of the others a hydrogen    atom or an unsubstituted or substituted C₁₋₈alkyl radical, a phenyl    group or a benzyl group, or-   R⁷ and R^(7′) together, and/or R⁸ and R⁸′ together, form, each pair    independently of the other, a carbonyl group or a thiocarbonyl    group, so that they can function as a cation to the oxonol dyes    according to the invention.

An example of such an ion pair is the composition M-11 indicated below:

Where the ammonium groups do not function as a cation to the oxonol dyesaccording to the invention, examples of anions are inorganic or organicanions, such as carboxylates, sulfonates, phenolates, phosphonates, Cl⁻,Br⁻, I⁻ and ClO₄ ⁻.

Special preference is given to compounds of formulae (I-5) and (I-6)wherein Me is Cu, Ni or Co; R⁵¹, R⁵², R⁵³, R⁵⁴, R⁶¹, R⁶², R⁶³ and R⁶⁴are a hydrogen atom, a chlorine or bromine atom, an amino group, aC₁₋₄alkylamino group, a di(C₁₋₄alkyl)amino group, a cyano group, ahydroxy group, a C₁₋₄alkyl radical, a C₁₋₁₆alkoxy radical which may beunsubstituted or substituted by a tri(C₁₋₄alkyl)ammonium group; aradical R¹¹⁰O—[CH₂CH₂—O—]_(X1) wherein R¹¹⁰ is a C₁₋₄alkyl radical andX1 is a number from 1 to 4; a carboxylic acid ester group, a phosphoricacid ester group, a carboxamide group, a sulfamide group, atri(C₁₋₄alkyl)ammonium group, a carboxylic acid or sulfonic acid orphosphoric acid group or a salt thereof, or R⁵¹ and R⁵² together, and/orR⁶¹ and R⁶² together, form an unsubstituted or substituted phenyl ring;R¹ and R⁴ are each independently of the other a hydrogen atom or aC₁₋₄alkyl radical; R² and R³ are a hydrogen atom or a C₁₋₄alkyl radicalor together form a double bond or a cyclohexane ring, especiallycompounds of formula (I-5) wherein the substituents are as defined inTable 1, which follows: TABLE 1 Ex. Cpd. R⁵¹ R⁵² R⁵³ R⁵⁴ R⁶¹ R⁶² R⁶³ R⁵⁴R¹ R⁴ R² R³ R^(2′) R^(3′) Me 29 M-1 H H H H H H ⁺N(CH₃)₃Y⁻ H CH₃ H H CH₃H CH₃ Cu Y⁻ 30 M-2 H H ⁺N(CH₃)₃Y⁻ H H H ⁺N(CH₃)₃Y⁻ H H H H H H H Cu 2Y⁻31 M-3 H H ⁺N(CH₃)₃Y⁻ H H H ⁺N(CH₃)₃Y⁻ H H H ¹⁾ ¹⁾ H H Cu 2Y⁻ 32 M-4 H HOCH₂CH₂— H H H OCH₂OH₂— H H H H H H H Cu 2Y⁻ ⁺N(CH₃)₃Y⁻ ⁺N(CH₃)₃Y⁻ 28M-5 H H H H H H H H H H H H H H Cu 33 M-6 H H H CH₃ H H H CH₃ H H H H HH Cu 34 M-7 H H H OCH₃ H H H OCH₃ H H H H H H Cu 35 M-8 H H OC₁₂H₂₅ H HH OC₁₂H₂₅ H H H H H H H Cu 36 M-9 H H OC₂H₄OCH₃ H H H OC₂H₄OCH₃ H H H HH H H Cu 37 M-10 H H OC₂H₄OC₂H₄OC₂H₅ H H H OC₂H₄OC₂H₄OC₂H₅ H H H H H H HCu 38 M-11 H H O-tert-C₄H₉ H H H O-tert-C₄H₉ H H H H H H H Cu 39 M-12 HH H H H H H H C₂H₅ C₂H₅ H H H H Cu 40 M-13 CH₃ H H CH₃ CH₃ H H CH₃ H H HH H H Cu 41 M-14 H H H H H H H H H H ¹⁾ ¹⁾ H H Cu 42 M-15 H H H H H H HH H H ¹⁾ ¹⁾ H H Co 43 M-16 H tert- H tert- H tert- H tert- H H ¹⁾ ¹⁾ H HNi C₄H₉ C₄H₉ C₄H₉ C₄H₉ 44 M-17 H H H H H H H H H H ¹⁾ ¹⁾ H H Ni 45 M-18H H NCH₃)₂ H H H N(CH₃)₂ H H H ¹⁾ ¹⁾ H H Ni 46 M-19 H H OP(O)OC₂H₅)₂ H HH OP(O)OC₂H₅)₂ H H H H H H H Cu 47 M-20 H SO₃- H H H SO₃- H H H H H H HH Cu Y1+ Y1+ 48 M-21 H H O-tert-C₄H₉ H H H O-tert-C₄H₉ H H H ²⁾ ²⁾ CN CNNi 49 M-22 H H H H H H H H H H ³⁾ ³⁾ ³⁾ ³⁾ Ni 50 M-23 ⁴⁾ ⁴⁾ H ⁵⁾ ⁴⁾ ⁴⁾ H⁵⁾ H H ²⁾ ²⁾ CN CN Ni′ ¹⁾R² and R³ together form a cyclohexane ring;²⁾R² and R³ together form a double bond; ³⁾R², R^(2′), R³, and R^(3′)together form a phenyl ring; ⁴⁾R⁵¹ and R⁵² together, and/or R⁶¹ and R⁶²together, form a phenyl ring; ⁵⁾—C(O)OCH₂CH₂OCH₂CH₂OH.

(idealised representation of Primene 81R ® (Rohm & Haas Company, mixtureof C₁₂₋₁₄amine isomers)The metal complexes of formula (I) described hereinbefore can beprepared in accordance with, or in analogy to, methods described inEP-A-200 843, EP-A-162 811, EP-A-362 139 and EP-A-436 470.

In accordance with the invention, oxonol dyes are understood to becompounds of the following general formulae

wherein X¹ is ═O, ═NR⁹ or ═C(CN)₂, R⁹ being a substituent; X² is —O,—NR⁹ or —C(CN)₂, R⁹ being a substituent; E and G are in each case agroup of atoms necessary for the formation of a chain having conjugateddouble bonds, x and y are 0 or 1, M^(k+) is an organic or inorganiccation, k is an integer from 1 to 10, and m is 0, 1, 2, 3 or 4, whichmeans that, in addition to true oxonol dyes (X¹, X²=0), derivatives ofoxonol dyes (X¹ and/or X²≠O) are also included.

More specifically, the oxonol dye is a compound of formula

wherein A¹, A², B¹ and B² are in each case a substituent; Y¹ and Z¹ arein each case a group of atoms necessary for the formation of acarbocyclic or heterocyclic ring; E and G are in each case a group ofatoms necessary for the formation of a chain having conjugated doublebonds; X¹ is ═, ═NR⁹ or ═C(CN)₂, R⁹ being a substituent; X² is —O, —NR⁹or —C(CN)₂, R⁹ being a substituent; L is a methine group, which may besubstituted, or a group by means of which a polymethine group iscompleted, it being possible for 3, 5 or 7 methine groups to beconnected in order to form a chain having conjugated double bonds, whichchain may be substituted; M^(k+) is an organic or inorganic cation, italso being possible for the metal complex of formula (I-1) or (I-2) tobe the cation provided it carries one or more positive charge(s); x andy are 0 or 1, and k is an integer from 1 to 10, with preference beinggiven to oxonol dyes of formula (II-2) over those of formula (II-1).

Examples of substituents denoted by the radicals A¹, A², B¹ and B² are:

-   a straight-chain or branched C₁₋₂₄alkyl radical, preferably    C₁₋₈alkyl radical, which may be unsubstituted or substituted, such    as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl,    sec-butyl, isobutyl, tert-butyl, cyclobutyl, n-pentyl, 2-pentyl,    3-pentyl, 2,2-dimethylpropyl, hexyl, heptyl, 2,4,4-trimethylpentyl,    2-ethylhexyl or octyl, ethoxycarbonylethyl, cyanoethyl,    diethylaminoethyl, chloroethyl, acetoxyethyl and trifluoromethyl,-   a straight-chain or branched C₂₋₂₄alkenyl radical, preferably    C₂₋₈alkenyl radical, which may be unsubstituted or substituted, such    as, for example, vinyl, allyl, 2-propen-2-yl, 2-buten-1-yl,    3-buten-1-yl, 1,3-butadien-2-yl, 2-penten-1-yl, 3-penten-2-yl,    2-methyl-1-buten-3-yl, 2-methyl-3-buten-2-yl, 3-methyl-2-buten-1-yl,    1,4-pentadien-3-yl, or any isomer of hexenyl, octenyl, nonenyl,    decenyl, dodecenyl, tetradecenyl, hexadecenyl, octadecenyl,    icosenyl, henicosenyl, docosenyl, tetracosenyl, hexadienyl,    octadienyl, nonadienyl, decadienyl, dodecadienyl, tetradecadienyl,    hexadecadienyl, octadecadienyl or icosadienyl,-   a straight-chain or branched C₁₋₂₄alkoxy radical, that is to say    O—C₁₋₂₄alkyl, such as, for example, methoxy, ethoxy, n-propoxy,    isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy,    n-pentyloxy, 2-pentyloxy, 3-pentyloxy, 2,2-dimethylpropoxy,    n-hexyloxy, n-heptyloxy, n-octyloxy, 1,1,3,3-tetramethylbutoxy or    2-ethylhexyloxy,-   a straight-chain or branched C₁₋₂₄alkylthio radical, that is to say    S—C₁₋₂₄alkyl radical, examples of a C₁₋₂₄alkylthio being the    examples indicated for a C₁₋₂₄alkoxy radical wherein the oxygen atom    of the ether bond is replaced by a sulfur atom,-   a C₆₋₂₄aryloxy radical, that is to say O—C₆₋₂₄aryl, such as, for    example, phenoxy or 4-methoxyphenyl,-   a C₆₋₂₄arylthio radical, that is to say S—C₆₋₂₄aryl, such as, for    example, phenylthio or 4-methoxyphenylthio,-   a straight-chain or branched C₂₋₂₄alkynyl radical, preferably    C₂alkynyl radical, which may be unsubstituted or substituted, such    as, for example, ethynyl, 1-propyn-3-yl, 1-butyn-4-yl,    1-pentyn-5-yl, 2-methyl-3-butyn-2-yl, 1,4-pentadiyn-3-yl,    1,3-pentadiyn-5-yl, 1-hexyn-6-yl, cis-3-methyl-2-penten-4-yn-1-yl,    trans-3-methyl-2-penten-4-yn-1-yl, 1,3-hexadiyn-5-yl, 1-octyn-8-yl,    1-nonyn-9-yl, 1-decyn-10-yl or 1-tetracosyn-24-yl,-   a C₂₋₁₈acyl radical, preferably C₂₋₈acyl radical, which is    unsubstituted or substituted, such as, for example, acetyl,    propionyl, butanoyl or chloroacetyl,-   a C₁₋₂₄alkylsulfonyl radical, preferably C₁₋₈alkylsulfonyl radical,    or C₆₋₂₄arylsulfonyl radical, preferably C₆₋₈arylsulfonyl radical,    which may be substituted, such as, for example, p-toluenesulfonyl,-   a C₃₋₂₄cycloalkyl radical, such as, for example, cyclopropyl,    cyclopropyl-methyl, cyclobutyl, cyclopentyl, cyclohexyl,    cyclohexyl-methyl, trimethylcyclohexyl, thujyl, norbornyl, bornyl,    norcaryl, caryl, menthyl, norpinyl, pinyl, 1-adamantyl, 2-adamantyl,    5α-gonyl or 5ξ-pregnyl,-   a C₆₋₂₄aryl radical, preferably C₆₋₁₀aryl radical, such as, for    example, phenyl, 4-methylphenyl, 4-methoxyphenyl, naphthyl,    biphenylyl, 2-fluorenyl, phenanthryl, anthryl or terphenylyl,-   a C₇₋₂₄aralkyl radical, preferably C₇₋₁₂aralkyl radical, which may    be substituted, such as, for example, benzyl, 2-benzyl-2-propyl,    β-phenethyl, 9-fluorenyl, α,α-dimethylbenzyl, ω-phenyl-butyl,    ω-phenyl-octyl, ω-phenyl-dodecyl or    3-methyl-5-(1′,1′,3′,3′-tetramethyl-butyl)-benzyl,-   a straight-chain or branched C₁₋₂₄alkoxycarbonyl radical, that is to    say C(O)O—C₁₋₂₄alkyl, preferably C(O)O—C₁₋₈alkyl, such as, for    example, methoxy-, ethoxy-, n-propoxy-, isopropoxy-, n-butoxy-,    sec-butoxy-, isobutoxy- or tert-butoxy-carbonyl,-   a C₆₋₂₄aryloxycarbonyl radical, that is to say C(O)O—C₇₋₂₄aryl,    preferably C(O)O—C₇₋₁₂aryl, such as, for example, phenoxycarbonyl,    4-methylphenoxycarbonyl or 4-methoxyphenoxycarbonyl,-   a C₂₋₁₈acyloxy radical, preferably C₂₋₈acyloxy radical, which may be    unsubstituted or substituted, such as, for example, acetoxy,    ethylcarbonyloxy, cyclohexylcarbonyloxy, benzoyloxy or    chloroacetoxy,-   a C₁₋₁₈carbamoyl radical, preferably C₁₋₈carbamoyl radical, which    may be unsubstituted or substituted, such as, for example,    carbamoyl, methylcarbamoyl, ethylcarbamoyl, n-butylcarbamoyl,    tert-butylcarbamoyl, dimethylcarbamoyloxy, morpholinocarbamoyl or    pyrrolidinocarbamoyl,-   a C₂₋₁₈carbamoyloxy radical, preferably C₂₋₈carbamoyloxy radical,    which may be unsubstituted or substituted, such as, for example,    methylcarbamoyloxy or diethylcarbamoyloxy,-   a sulfamoyl group having from 0 to 18, preferably from 0 to 8,    carbon atoms, which may be unsubstituted or substituted, such as,    for example, sulfamoyl, methylsulfamoyl or phenylsulfamoyl,-   a heterocyclic ring having from 3 to 12 carbon atoms, for example    2-thienyl, 2-furyl, 1-pyrazolyl, 2-pyridyl, 2-thiazolyl, 2-oxazolyl,    2-imidazolyl, isothiazolyl, triazolyl and any other ring system    consisting of thiophene, furan, pyrazole, thiazole, oxazole,    imidazole, isothiazole, thiadiazole, triazole, pyridine or benzene    rings unsubsttuted or substituted by from 1 to 6 ethyl, methyl,    ethylene and/or methylene substituents,-   a halogen atom, such as fluorine, chlorine or bromine,-   a hydroxy group, a nitro group, a cyano group or a carboxy group, or    an amino group —NR¹⁰⁶R¹⁰⁷ wherein R¹⁰⁶ and R¹⁰⁷ are each    independently of the other a hydrogen atom, a C₁₋₂₄alkyl radical,    C₁₋₂₄alkylcarbonyl radical, C₁₋₂₄alkoxycarbonyl radical, C₆₋₂₄aryl    radical, C₇₋₂₄aralkyl radical, C₆₋₂₄arylcarbonyl radical, a    C₆₋₂₄aryloxycarbonyl radical, C₆₋₂₄arylthiocarbonyl radical, such    as, for example, amino, methylamino, ethylamino, dimethylamino,    diethylamino, phenylamino, methoxycarbonylamino, acetylamino,    ethylcarbonylamino, cyclohexylcarbonylamino, benzoylamino or    chloroacetylamino, or R¹⁰⁶ and R¹⁰⁷ together form a five- to    seven-membered heterocyclic ring, such as morpholino, piperidino or    pyrrolidino.

When a radical may be unsubstituted or substituted, examples ofsubstituents are those substituents mentioned above which may be denotedby the radicals A¹, A², B¹ and B². X¹ is ═O, ═NR⁹ or ═C(CN)₂, preferably═O, and X² is —O, —NR⁹ or —C(CN)₂, preferably —O, examples of asubstituent R⁹ being the examples given above for A¹, A², B¹ and B². Thegroup =L- can in general be represented by the following formula:

wherein R³⁰, R³¹, R³², R³³, R₃₄, R³⁵ and R³⁶ are each independently ofthe others a hydrogen atom, a halogen atom, such as fluorine, chlorineor bromine, an unsubstituted or substituted C₁₋₈alkyl radical, forexample a C₁₋₈perfluoroalkyl radical such as trifluoromethyl, anunsubstituted or substituted C₆₋₁₀aryl radical, such as phenyl, anunsubstituted or substituted C₇₋₁₀aralkyl radical, such as benzyl orp-methoxybenzyl, or a heterocyclic ring having from 2 to 10 carbonatoms, an unsubstituted or substituted C₁₋₄alkoxy radical, such as amethoxy group, a cycloalkyloxy group, such as a cyclohexyloxy group, anamino group —NR¹⁰⁶R¹⁰⁷, R¹⁰⁸ and R¹⁰⁷ being as defined hereinbefore, analkylcarbonyloxy radical, such as an acetoxy group, an alkylthioradical, such as a methylthio group, an arylthio radical, such as aphenylthio group, a cyano group or a nitro group, or

-   two substituents R³⁰, R³¹, R³², R³³, R³⁴, R³⁵ and R³⁶, which are    located in 1,3-positions relative to one another, together form an    unsubstituted or substituted carbocyclic ring having 5 or 6 carbon    atoms, such as cyclohexenyl or cyclopentenyl, which may be    unsubstituted or substituted by one or more C₁₋₄alkyl and/or    C₁₋₄alkoxy radicals,-   p, q and rare 0 or 1.

L is preferably selected from the following group:

wherein p and q are each independently of the other 0 or 1, Y is ahydrogen atom, an unsubstituted or substituted C₁₋₄alkyl radical, suchas a methyl or trifluoromethyl group, an unsubstituted or substitutedC₇₋₁₂aralkyl radical, such as a benzyl or p-methoxybenzyl group, anunsubstituted or substituted C₆₋₁₂aryl radical, such as a phenyl,m-chlorophenyl or naphthyl group, an unsubstituted or substitutedC₁₋₄alkoxy radical, such as a methoxy group, a C₅₋₇cycloalkyloxy group,such as a cyclohexyloxy group, a disubstituted amino group —NR¹⁰⁶R¹⁰⁷,R¹⁰⁸ and R¹⁰⁷ being as defined hereinbefore except for a hydrogen atom,such as a dimethyl, diphenyl or methylphenyl group, morpholino,imidazolino or ethoxycarbonyl-piperidino group, an alkylcarbonyloxyradical, such as an acetoxy group, an alkylthio radical, such as amethylthio group, an arylthio radical, such as a phenylthio group, acyano group, a nitro group, or a halogen atom, such as a fluorine,chlorine or bromine atom. Special preference is given to Y being ahydrogen atom, a chlorine atom or a p-methylphenyl group and L being agroup L-2 or L-4.

Examples of a carbocyclic or heterocyclic ring are as follows:

(A-47), wherein Ra, Rb and Rc may, each independently of the others, beas defined hereinbefore for A¹, A², B¹ and B².

The rings comprising Y¹, (E)^(x) and X¹, and Z¹, (G)^(y) and X² informula II-2 may be the same or different. For example, when synthesisstarts from two differently substituted groups (A-9) and (A-9′), threecompounds can, in principle, be formed, namely compounds having twogroups (A-9) or two groups (A-9′) and compounds having both an (A-9) andan (A-9′) group. Mixtures of that kind may also be used as oxonol dyesin accordance with the invention. The expression “at least one oxonoldye” may include any number of oxonol dyes but generally means from 1 to5, preferably 1, 2 or 3, oxonol dye(s).

Of the groups (A-1) to (A-47) mentioned hereinbefore, preference isgiven to the groups (A 5), (A-6), (A-7), (A-11) and (A-14), and specialpreference to (A-9).

M^(k+) is an organic or inorganic cation. Examples of cations that arerepresented by M^(k+) are hydrogen cations, metal cations, such as asodium, potassium, lithium, calcium, iron and copper ion, a metalcomplex cation, an ammonium cation, including cationic dyes and apyridinium cation, an oxonium, sulfonium, phosphonium, selenium andiodonium ion. In accordance with the invention, the cation is generallyselected from ammonium cations, cationic dyes and metal complexes offormulae (I-1), (I-2), (I-3), (I-4), (I-5) and (I-6) that aresubstituted by a cationic group.

In principle, any cationic dye may be used. For DVD, cationic dyeshaving an absorption maximum in the range from 550 to 620 nm arepreferred and, for DVR, cationic dyes having an absorption maximum atless than 450 nm are preferred. Examples of such cationic dyes aremethine dyes, especially cyanine dyes, such as zero-, mono-, di-, tri-and penta-methine cyanine dyes and also higher vinylogous cyanine dyes(for example, see Ullmanns Enzyklopadie der Technischen Chemie, 4thEdition (1978), Volume 16, p. 650-656; 5th Edition, Volume A 16,509-517), triaryl- and diaryl-methane dyes, such as diphenyl- andtriphenyl-methane dyes and xanthene dyes (for example, see UllmannsEnzyklopadie der Technischen Chemie, 4th Edition (1978), Volume 23, p.387-388, 389-405 and 408415; 5th Edition, Volume A 27, p. 186-188,189-204 and 209-218) and azine dyes, such as phenazine, oxazine andthiazine dyes (for example, see Ullmanns Enzyklopadie der TechnischenChemie, 5th Edition (1985), Volume A3, p. 216-223, 224-229 and 229-235).In accordance with the invention, preference is given to the polymethinedyes of formula

described in WO98/28737, wherein

-   A₁ and A₂ are each independently of the other C(CH₃)₂, O, S, Se or    unsubstituted or C₁-C₅alkyl- or benzyl-substituted CH═CH;-   Q is CR⁸⁵, CR⁸⁵, CR⁸⁶═CR⁸⁷ or CR⁸⁵—CR⁸⁶═CR⁸⁷—CR⁸⁸═CR⁸⁹,-   R⁷¹ and R⁷² are each independently of the other C₁₋₁₂alkyl or    C₂₋₁₂alkenyl each unsubstituted or substituted one or more times by    halogen, hydroxy, C₁₋₁₂alkoxy or by cyano, or C₆₋₁₂aryl or    C₇₋₁₂aralkyl each unsubstituted or substituted by a radical R⁷⁷ or    by two radicals R⁷⁷ and R⁷⁸;-   R⁷³, R⁷⁴, R⁷⁵ and R⁷⁶ are each independently of the others hydrogen,    halogen, nitro, cyano, hydroxy, amino, NHR⁷⁹, NR⁷⁹R⁸⁰, CONH₂,    CONHR⁷⁹, CONR⁷⁹R⁸⁰, SO₂C₁-C₁₂alkyl, SO₂NH₂, SO₂NHR⁷⁹, SO₂NR⁷⁹R⁸⁰,    COOH, COOR⁸¹, NHCOR⁸², NR⁸¹COR⁸², NHCOOR⁸²,-   NR⁸¹COOR⁸², or unsubstituted or mono- or poly-halo-, -hydroxy- or    -cyano-substituted C₁₋₁₂alkyl, C₁₋₁₂alkylthio or C₁₋₁₂alkoxy; or-   R⁷³ and R⁷⁴ together, and/or R⁷⁵ and R⁷⁶ together, in pairs, are    1,4-buta-1,3-dienylene unsubstituted or substituted by a radical R⁸³    or by two radicals R⁸³ and R⁸⁴ so that a naphthyl is formed together    with the common phenyl;-   R⁸⁵, R⁸⁵, R⁸⁷, R⁸⁸ and R⁸⁹ are each independently of the others    hydrogen, halogen, C₁₋₁₂alkoxy, unsubstituted or mono- or    poly-halo-, -hydroxy- or -cyano-substituted C₁₋₁₂alkyl, C₆-C₁₂aryl,    C₇-C₁₂aralkyl or NR⁷⁹R⁸⁰; or-   R⁸⁵ and R⁸⁷ together, R⁸⁶ and R⁸⁸ together, or R⁸⁷ and R⁸⁹ together,    in pairs, are ethylene, ethylidene, propylene, propylidene,    o-phenylene, α,2-benzylidene or 1,8-naphthylidene each unsubstituted    or substituted by a radical R⁸³ or by two radicals R⁸³ and R⁸⁴;-   R⁷⁷ and R⁷⁸ are each independently of the other hydrogen, halogen,    nitro, cyano, hydroxy, amino, NHR⁷⁹, NR⁷⁹R⁸⁰, CONH₂, CONHR⁷⁹,    CONR⁷⁹R⁸⁰, SO₂C₁₋₁₂alkyl, SO₂NH₂, SO₂NHR⁷⁹, SO₂NR⁷⁹R⁸⁰, COOH,    COOR⁸¹, NHCOR⁸², NR⁸¹COR⁸², NHCOOR⁸², NR⁸¹COOR⁸², or C₁₋₁₂alkyl,    C₁₋₁₂alkylthio or C₁₋₁₂alkoxy each unsubstituted or substituted one    or more times by halogen, hydroxy or by cyano;-   R⁷⁹ and R⁸⁰ are each independently of the other C₁₋₁₂alkyl or    C₂₋₁₂alkenyl each unsubstituted or substituted one or more times by    halogen, hydroxy or by C₁₋₂alkoxy, or C₆-C₁₂aryl or C₇-C₁₂aralkyl    each unsubstituted or substituted by a radical R⁸³ or by two    radicals R⁸³ and R⁸⁴; or-   R⁷⁹ and R⁸⁰ are, together with the common N, pyrrolidine,    piperidine, piperazine or morpholine each unsubstituted or    substituted one to four times by C₁₋₄alkyl, or carbazole,    phenoxazine or phenothiazine each unsubstituted or substituted by a    radical R⁸³ or by two radicals R⁸³ and R⁸⁴;-   R⁸¹ and R⁸² are each independently of the other C₁₋₁₂alkyl or    C₂₋₁₂alkenyl each unsubstituted or substituted one or more times by    halogen, hydroxy or by C₁₋₁₂alkoxy, or C₆-C₁₂aryl or C₇-C₁₂aralkyl    each unsubstituted or substituted by a radical R⁸³ or by two    radicals R⁸³ and R⁶⁴.-   R⁸³ and R⁸⁴ are each independently of the other halogen, nitro,    cyano, hydroxy, NR⁹⁰R⁹¹, CONH₂, CONHR⁹⁰, CONR⁹⁰R⁹¹, SO₂C₁₋₁₂alkyl,    SO₂NR⁹⁰R⁹¹, COOH, COOR⁹², NHCOR⁹³, NHCOOR⁹³, NR⁹²COR⁹³, NR⁹²COOR⁹³,    or C₁₋₁₂alkyl or C₁₋₁₂alkoxy each unsubstituted or substituted one    or more times by halogen;-   R⁹⁰ and R⁹¹ are each independently of the other hydrogen, C₆₋₁₂aryl,    C₇₋₁₂aralkyl; or C₁₋₁₂alkyl or C₂₋₁₂alkenyl each unsubstituted or    substituted one or more times by halogen, hydroxy or by C₁₋₁₂alkoxy;    or-   R⁹⁰ and R⁹¹ are, together with the common N, pyrrolidine,    piperidine, piperazine or morpholine each unsubstituted or    substituted one to four times by C₁₋₄alkyl; or carbazole,    phenoxazine or phenothiazine; and-   R⁹² and R⁹³ are each independently of the other C₆₋₁₂aryl,    C₇₋₁₂aralkyl, or C₁₋₁₂alkyl or C₂₋₁₂alkenyl each unsubstituted or    substituted one or more times by halogen, hydroxy or by C₁₋₁₂alkoxy.    Preference is given to the compounds CY-1-CY-24 described in    Examples A1 to A24 of WO98/28737.

Examples of preferred compositions wherein the cation is a cyanine dyeare the compositions D-50 and D-51 described in Examples 25 and 26:

In principle, those metal complexes of formula (I-1) or (I-2) that aresubstituted by one or more cationic groups, especially ammonium groups,are suitable as the cation M^(k+).

-   M^(k+) may also be an ammonium cation of formula ⁺NR¹¹R¹²R¹³R¹⁴,    wherein R¹¹, R¹², R¹³ and R¹⁴ are a hydrogen atom, a straight-chain    or branched C₁₋₆alkyl radical, preferably C₁₋₁₆alkyl radical, which    may be unsubstituted or substituted, such as, for example, methyl,    ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl,    tert-butyl, cyclobutyl, n-pentyl, 2-pentyl, 3-pentyl,    2,2-dimethylpropyl, hexyl, heptyl, 2,4,4-trimethylpentyl,    2-ethylhexyl or octyl, ethoxycarbonylethyl, cyanoethyl,    diethylaminoethyl, chloroethyl, acetoxyethyl and trifluoromethyl,-   a straight-chain or branched C₂₋₃₆alkenyl radical, preferably    C₂₋₁₆alkenyl radical, which may be unsubstituted or substituted,    such as, for example, vinyl, allyl, 2-propen-2-yl, 2-buten-1-yl,    3-buten-1-yl, 1,3-butadien-2-yl, 2-penten-1-yl, 3-penten-2-yl,    2-methyl-1-buten-3-yl, 2-methyl-3-buten-2-yl, 3-methyl-2-buten-1-yl,    1,4-pentadien-3-yl, or any isomer of hexenyl, octenyl, nonenyl,    decenyl, dodecenyl, tetradecenyl, hexadecenyl, octadecenyl,    icosenyl, henicosenyl, docosenyl, tetracosenyl, hexadienyl,    octadienyl, nonadienyl, decadienyl, dodecadienyl, tetradecadienyl,    hexadecadienyl, octadecadienyl or icosadienyl,-   a C₂₋₃₆acyl radical, preferably C₂₋₁₆acyl radical, which may be    unsubsttuted or substituted, such as, for example, acetyl,    propionyl, butanoyl or chloroacetyl,-   a C₁₋₂₄alkylsulfonyl radical, preferably C₁₋₁₆alkylsulfonyl radical,    or C₆₋₂₄arylsulfonyl radical, preferably C arylsulfonyl radical,    each of which may be substituted, such as, for example,    p-toluenesulfonyl,-   a C₃₋₂₄cycloalkyl radical, which may be substituted, such as, for    example, cyclopropyl, cyclopropyl-methyl, cyclobutyl, cyclopentyl,    cyclohexyl, cyclohexyl-methyl, trimethyl-cyclohexyl, thujyl,    norbornyl, bornyl, norcaryl, caryl, menthyl, norpinyl, pinyl,    1-adamantyl, 2-adamantyl, 5 α-gonyl or 5ξ-pregnyl,-   a C₆₋₂₄aryl radical, preferably C₆₋₁₀aryl radical, which may be    substituted, such as, for example, phenyl, 4-methylphenyl,    4-methoxyphenyl, naphthyl, biphenylyl, 2-fluorenyl, phenanthryl,    anthryl or terphenylyl,-   a C₇₋₂₄aralkyl radical, preferably C₇₋₁₂aralkyl radical, which may    be substituted, such as, for example, benzyl, 2-benzyl-2-propyl,    β-phenethyl, 9-fluorenyl, α,α-dimethylbenzyl, ω-phenyl-butyl,    ω-phenyl-octyl, ω-phenyl-dodecyl or    3-methyl-5-(1′,1′,3′,3′-tetramethyl-butyl)-benzyl,-   a straight-chain or branched C₁₋₂₄alkoxycarbonyl radical, that is to    say C(O)O-C₁₋₂₄alkyl, preferably C(O)O—C₁₋₈alkyl, such as, for    example, methoxy-, ethoxy-, n-propoxy-, isopropoxy-, n-butoxy-,    sec-butoxy-, isobutoxy- or tert-butoxy-carbonyl, or a heterocyclic    ring having from 3 to 12 carbon atoms, for example 2-thienyl,    2-furyl, 1-pyrazolyl, 2-pyridyl, 2-thiazolyl, 2-oxazolyl,    2-imidazolyl, isothiazolyl, triazolyl or any other ring system    consisting of thiophene, furan, pyrazole, thiazole, oxazole,    imidazole, isothiazole, thiadiazole, triazole, pyridine or benzene    rings unsubstituted or substituted by from 1 to 6 ethyl, methyl,    ethylene and/or methylene substituents.

Primary, secondary, tertiary and also quaternary ammonium cations aresuitable.

The tetravalent nitrogen may also be a member of a 5- or 6-memberedring. Those systems may also contain additional hetero atoms, such as,for example, S, N and O. Examples of such systems are ammonium cationsthat are derived from 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) and1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

Also suitable are polyammonium salts having from 1 to 10, especiallyfrom 2 to 4, ammonium cations, in which case the substituents describedabove for the “mono” compounds may be present at the nitrogen and thetetravalent nitrogen may also be a member of a 5- or 6-membered ring(for example, see formulae VI-3 to VI-8 given hereinbelow).

By way of example, the compounds B1 to B180 mentioned in U.S. Pat. No.6,225,024 are examples of quaternary ammonium cations.

Preference is given to the following ammonium cations:

wherein R¹⁰, R¹⁰′ and R¹⁰″ are each independently of the others ahydrogen atom, a C₃₋₂₄cycloalkyl radical which is unsubstituted orsubstituted, for example by from one to three C₁₋₄alkyl radicals, suchas cyclohexyl or 3,3,5-trimethylcyclohexyl or rosin amine D, or astraight-chain or branched C₁₋₂₄alkyl radical, R¹¹, R¹², R¹³ and R¹⁴ area hydrogen atom, a straight-chain or branched C₁₋₃₆alkyl radical,preferably C₁₋₁₆alkyl radical, which may be unsubstituted orsubstituted, the total number of carbon atoms in the radicals R¹¹, R¹²,R¹³ and R¹⁴ being in the range from 4 to 36, preferably from 8 to 22,with special preference being given, because of their steric shielding,to ammonium cations that are derived from 2,6-di-tert-butylpyridinium orprimary aliphatic amines having highly branched alkyl chains wherein theamine nitrogen is bonded to a tertiary carbon atom, such as PRIMENE81-R® (Rohm & Haas Company; mixture of amine isomers having from 12 to14 carbon atoms) or PRIMENE JM-T® (Rohm & Haas Company; mixture of amineisomers having from 16 to 22 carbon atoms) or ethyldiisopropylamine(Hünig's base), or are a straight-chain or branched hydroxy-C₁₋₃₆alkylradical, especially hydroxy-C₁₋₈alkyl radical, C₆₋₂₄aryl radical,especially C₆₋₁₀aryl radical, or C₇₋₂₄aralkyl radical, especiallyC₇₋₁₂aralkyl radical, or two of the radicals R¹¹, R¹², R¹³ and R¹⁴,together with the nitrogen atom to which they are bonded, form a five-or six-membered heterocyclic ring, such as pyrrolidino, piperidino ormorpholino; or

wherein R⁶⁷ and R⁶⁸ are each independently of the other a substituent,R⁶⁵ and R⁶⁶ are each independently of the other a substituted orunsubstituted alkyl radical, a substituted or unsubstituted alkenylradical, a substituted or unsubstituted alkynyl radical, a substitutedor unsubstituted aralkyl radical, a substituted or unsubstituted arylradical or a substituted or unsubstituted heterocyclic radical, it beingpossible for the pairs R⁶⁷ and R⁶⁸, R⁶⁷ and R⁶⁵, R⁶⁸ and R⁶⁶, and R⁶⁵and R⁶⁶ to be connected to form a ring, and s and t are eachindependently of the other 0 or an integer from 1 to 4, provided thatwhen s and t have a value of 2 or more the groups R⁶⁷ and R⁶⁸ may be thesame or different (U.S. Pat. No. 6,225,024); or of formula

(VI-6) wherein R⁶⁹ is a straight-chain or branched C₁₋₈alkyl radical,especially methyl, ethyl, propyl, butyl or tert-butyl, which may beunsubstituted or substituted, for example by a cyano group, a halogenatom or by a C₁₋₄alkoxy radical;

wherein R²⁰¹, R²⁰² and R²⁰³ are each independently of the others ahydrogen atom, a straight-chain or branched C₁₋₃₆alkyl radical,preferably C₁₋₁₆alkyl radical, which may be unsubstituted orsubstituted, a hydroxy-C₁₋₃₆alkyl radical, especially hydroxy-C₁₋₈alkylradical, which is unsubsttuted or substituted by one or more C₁₋₄alkyland/or C₁₋₄alkoxy radicals, a C₃₋₂₄cycloalkyl radical, especiallyC₅₋₇cycloalkyl radical, a C₆₋₂₄aryl radical, especially C₆₋₁₀arylradical, or a C₇₋₂₄aralkyl radical, especially C₇₋₁₂aralkyl radical, ortwo of the radicals R²⁰¹, R²⁰² and R²⁰³, together with the nitrogen atomto which they are bonded, form a five- or six-membered heterocyclicring, R²⁰⁴ is a hydrogen atom, a C₁₋₄alkyl or C₁₋₄alkoxy radical, u andv are integers from 1 to 3, the sum of u and v being 3, 4 or 5, and

-   X is a divalent connecting group, for example a C₁₋₈alkylene radical    which is unsubstituted or substituted by one or more C₁₋₄alkyl    and/or C₁₋₄alkoxy radicals, or a group    wherein R²⁰⁴ is as defined hereinbefore, Ar is a C₆₋₁₀aryl radical    which is unsubsttuted or substituted by one or more C₁₋₄alkyl and/or    C₁₋₄alkoxy radicals, Cy is a C₅₋₇cycloalkyl radical which is    unsubstituted or substituted by one or more C₁₋₄alkyl and/or    C₁₋₄alkoxy radicals, and t is an integer from 0 to 4.    -   Diammonium compounds of formula VI-7 are derived especially from        the following amines: 1,2-diaminoethane,        1,2-diamino-1-methylethane, 1,2-diamino-1,2-dimethylethane,        1,2-diamino-1,1-dimethylethane, 1,2-diaminopropane,        1,3-diaminopropane, 1,3-diamino-2-hydroxypropane,        N-methyl-1,2-diaminoethane, 1,4-diazacyclohexane,        1,2-diamino-1,1-dimethylethane, 2,3-diaminobutane,        1,4-diaminobutane, N-hydroxyethyl-1,2-diaminoethane,        1-ethyl-1,3-diaminopropane, 2,2-dimethyl-1,3-diaminopropane,        1,5-diaminopentane, 2-methyl-1,5-diaminopentane,        2,3-diamino-2,3-dimethylbutane, N-2-aminoethylmorpholine,        1,6-diaminohexane, 1,6-diamino-2,2,4-trimethylhexane,        N,N-dihydroxyethyl-1,2-diaminoethane,        N,N-dimethyl-1,2-diaminoethane, 4,9-dioxa-1,12-diaminododecane,        1,2-diaminocyclohexane, 1,3-diamino-4-methylcyclohexane,        1,2-diaminocyclohexane,        1-amino-2-aminomethyl-2-methyl-4,4-dimethylcyclohexane,        1,3-diaminomethylcyclohexane, N-2-aminoethylpiperazine,        1,1-di(4-aminocyclohexyl)methane, 1,1-di(4-aminophenyl)methane,        N,N′-diisopropyl-p-phenylenediamine,        N,N′-di-sec-butyl-p-phenylenediamine,        N,N′-bis(1,4-dimethyl-pentyl)-p-phenylenediamine,        N,N′-bis(1-ethyl-3-methyl-pentyl)-p-phenylenediamine,        N,N′-bis(1-methyl-heptyl)-p-phenylenediamine,        N,N′-dicyclohexyl-p-phenylenediamine,        N,N′-diphenyl-p-phenylenediamine,        N,N′-di(2-naphthyl)-p-phenylenediamine,        N-isopropyl-N′-phenyl-p-phenylenediamine,        N-(1,3-dimethyl-butyl)-N′-phenyl-p-phenylenediamine,        N-(1-methyl-heptyl)-N′-phenyl-p-phenylenediamine,        N-cyclohexyl-N′-phenyl-p-phenylenediamine and        N,N′-dimethyl-N,N′-di-sec-butyl-p-phenylenediamine.

Special preference is given to the following compounds:

Suitable oxonol dyes are the oxonol dyes of formulae

-   -   are described in EP-A-0 833 314,

-   and wherein A¹, A², B¹, B²; E, G, Y¹, Z¹; X¹, X², M_(k+), m, n, x, y    and k are as defined hereinbefore and L¹, L², L³, L⁴ and LS are a    methine group, which may have a substituent. It should be noted    that, in contrast to the oxonol dyes described in EP-A-833 314,    wherein M^(k+) is an onium ion containing a positively charged onium    ion to which no hydrogen atom is bonded (quaternary ammonium ion)    (cf. Comparison Example 5 of EP-A-833 314, where it is shown that    the use of tertiary ammonium cations does not result in adequate    modulation factors or light-fastness properties), in accordance with    the invention there may in general be used as M^(k+) an organic or    inorganic cation, that is to say, for example a primary, secondary    or tertiary ammonium cation may also be used. Preference is given to    oxonol dyes of formula (II-4) over those of formula (II-3).

Preference is further given to oxonol dyes of the following formulae:

wherein Ra is CO₂C₁₋₄alkyl, cyano, CF₃, C(O)NHC₁₋₄alkyl, C(O)NHphenyl,phenyl, OH, C₁₋₄alkyl, C₁₋₄alkoxy, NHC(O)C₁₋₄alkyl, NHC(O)phenyl,C(O)NHC₁₋₄alkyl, C(O)NHphenyl, NHC(O)OC₁₋₄alkyl, NHC(O)Ophenyl or NH₂,

-   Rb is H, C₁alkyl, phenyl, hydroxyalkyl, C(O)NHC₁₋₄alkyl,    C(O)NHphenyl, o-methylphenyl, benzyl or 2,4,6-trichlorophenyl, and-   Y is H, C₁₋₄alkyl, phenyl, benzyl, C(O)NH₂ or halogen, such as    chlorine or bromine,    wherein Ra is H, phenyl or C₁₋₄alkyl,-   Rb is H, C₁₋₄alkyl, phenyl, hydroxy-C₁₋₄alkyl, o-methylphenyl or    benzyl and-   Y is H, C₁₋₄alkyl, phenyl, benzyl, C(O)NH₂ or halogen, such as    chlorine or bromine,-   X, k and M^(k+) being as defined hereinbefore.

Also suitable are the oxonol dyes of formula

described in U.S. Pat. No. 6,225,024, wherein R²¹, R²², R²³ and R²⁴ areeach independently of the others a hydrogen atom, a substituted orunsubsttuted alkyl radical, a substituted or unsubstituted aryl radical,a substituted or unsubstituted aralkyl radical or a substituted orunsubstituted heterocyclic radical, L²¹, L²² and L²³ are eachindependently of the others a methine group which may have asubstituent, m is an integer 0, 1, 2 or 3, M^(k+) is an organic orinorganic cation, and k is an integer from 1 to 10, preferably from 1 to4, provided that when m is 2 or 3 the groups L²² and L²³ may be the sameor different.

Special preference is given to the compounds of formula

wherein R²¹, R²², R²³ and R²⁴ are each independently of the others ahydrogen atom, a C₁₋₈alkyl radical, a C₁₋₈perfluoroalkyl radical, suchas trifluoromethyl, a C₁₋₈alkenyl radical, a C₁₋₄alkoxy-C₁₋₄alkylradical, a hydroxy-C₁₋₄alkyl radical, a R¹⁰⁴R¹⁰⁵N-C₁₋₄alkyl radical,R¹⁰⁴ and R¹⁰⁵ being as defined hereinbefore, a C₆₋₁₀aryl radical, suchas phenyl, a C₇₋₁₀aralkyl radical, such as benzyl, or a heterocyclicring having from 2 to 10 carbon atoms, or

-   R²¹ and R²² together, and/or R²³ and R²⁴ together, form an    unsubstituted or substituted carbocyclic ring, preferably having    from 3 to 10 carbon atoms, such as cyclopropyl, cyclobutyl,    cyclopentyl, cyclohexyl, 2-methylcyclohexyl, cycloheptyl or    cyclooctyl, or an unsubstituted or substituted heterocyclic ring,    preferably having from 2 to 10 carbon atoms, such as piperidyl,    chromanyl or morpholyl, which rings may be unsubstituted or    substituted by one or more C₁alkyl and/or C₁₋₄alkoxy radicals,-   R³⁰, R³¹, R³², R³³, R³⁴, R³⁵ and R³⁶ are each independently of the    others a hydrogen atom, a halogen atom, such as chlorine or bromine,    a C₁₋₈alkyl radical, a C₁₋₈perfluoroalkyl radical, such as    trifluoromethyl, a C₆₋₁₀aryl radical, such as phenyl, a C₇₋₁₀aralkyl    radical, such as benzyl, or a heterocyclic ring having from 2 to 10    carbon atoms, or-   two substituents R³⁰, R³¹, R³², R³³, R³⁴, R³⁵ and R³⁶, which are    located in 1,3-positions relative to one another, together form an    unsubstituted or substituted carbocyclic ring having 5 or 6 carbon    atoms, such as cyclohexenyl or cyclopentenyl, which may be    unsubstituted or substituted by one or more C₁₋₄alkyl and/or    C₁₋₄alkoxy radicals,-   p, q and r are 0 or 1 and M^(k+) is an organic or inorganic cation    and k is an integer from 1 to 10, preferably from 1 to 4.

It should be noted that, according to U.S. Pat. No. 6,225,024, theoxonol dyes described in EP-A-833 314, in contrast to the oxonol dyesdescribed in U.S. Pat. No. 6,225,024, when used in DVD recording media,do not produce adequate recording and reading properties because of lowreflectivity and a low degree of modulation and do not meet therequirements in terms of light-fastness because errors occur in the caseof prolonged irradiation, with reduced reading performance.

Oxonol dyes of the following general formula

wherein R³⁰, R³¹, R³², R³³, R³⁴, R³⁵ and R³⁶, p, q and r, M^(k+) and kare as defined above and R⁴¹ and R⁴¹′ are each independently of theother a hydrogen atom, an unsubstituted or substituted C₁₋₁₂alkylradical, C₅₋₇cycloalkyl, C₆₋₁₂aryl, C₇₋₁₂aralkyl radical or heterocyclicradical,

-   R⁴² and R^(42′) are each independently of the other a hydrogen atom,    a cyano group, a group C(O)OR⁴⁶, C(O)NR⁴⁸R⁴⁷ or C(O)R⁴⁷, an    unsubstituted or substituted C₁₋₁₂alkyl radical, C₅₋₇Cycloalkyl,    C₆₋₁₂aryl, C₇₋₁₂aralkyl radical or heterocyclic radical, R⁴⁶ and R⁴⁷    being an unsubstituted or substituted C₁₋₁₂alkyl radical,    C₅₋₇cycloalkyl, C₆₋₁₂aryl, C₇₋₁₂aralkyl radical or heterocyclic    radical, or R⁴⁶ and R⁴⁷, together with the nitrogen atom to which    they are bonded, forming a five- or six-membered ring, and-   R⁴³ and R^(43′) are each independently of the other a hydrogen atom,    a carboxylic acid group or an alkyl radical; are preferred.

Special preference is given to oxonol dyes of the following generalformula

wherein M^(k+) is an ammonium cation, such as K-1, K-2, K-3, K-4, M-1,M-2, M-3 or M-4, k is an integer from 1 to 4, especially 1 or 2,

-   R⁴¹ and R^(41′) are each independently of the other a hydrogen atom,    a C₁₋₄alkyl radical, such as methyl or ethyl, or a    perfluoro-C₁₋₄alkyl radical, such as trifluoromethyl, a    hydroxy-C₁₋₄alkyl radical, or a C₁₋₈alkyl radical interrupted one or    more times by —O—, such as-   CH₂CH₂CH₂—O—CH(CH₃)₂, a C₆₋₁₀aryl radical, such as phenyl, or a    C₇₋₁₂aralkyl radical, such as benzyl,-   R⁴² and R^(42′) are each independently of the other a hydrogen atom,    a cyano or carboxamide group,-   R⁴³ and R^(43′) are each independently of the other a hydrogen atom,    a carboxylic acid group or a salt thereof or a C₁₋₄alkyl radical,-   R⁴⁴ and R^(44′) are each independently of the other a hydrogen atom,    a C₁₋₄alkyl radical, a C₆₋₁₂aryl or C₇₋₁₂aralkyl radical, or-   R₄₄ and R_(44′) together form a five-membered or six-membered ring,    such as a cyclohexenyl or cyclopentenyl ring, and-   R⁴⁵ is a hydrogen atom, a halogen atom, especially a chlorine atom,    an unsubstituted or C₁₋₄alkyl- or C₁₋₄alkoxy-substituted C₆₋₁₂aryl    radical, such as phenyl or p-methylphenyl, or C₇₋₁₂aralkyl radical,    such as benzyl.

Moreover, oxonol dyes of the following general formula

wherein R^(a), R^(b), R^(a′) and R^(b′) are each independently of theother a hydrogen atom, a C₁₋₈alkyl radical, in particular a C₁₋₄alkylradical, a hydroxy-C₁₋₈alkyl radical, a C₁₋₈alkenyl radical, such as—CH₂—CH═CH₂, an unsubstituted or C₁₋₄alkyl- or C₁₋₄alkoxy-substitutedC₆₋₁₂aryl, such as phenyl, or C₇₋₁₂aralkyl radical, such as benzyl,

-   R⁴⁴ and R^(44′) are each independently of the other a hydrogen atom,    a C₁₋₄alkyl radical, a C₆₋₁₂aryl or C₇₋₁₂aralkyl radical, or-   R⁴⁴ and R^(44′) together form a five-membered or six-membered ring,    such as a cyclohexenyl or cyclopentenyl ring, and-   R⁴⁵ is a hydrogen atom, a halogen atom, especially a chlorine atom,    an unsubstituted or C₁₋₄alkyl- or C₁₋₄alkoxy-substituted C₆₋₁₂aryl    radical, such as phenyl or p-methylphenyl, or C₇₋₁₂aralkyl radical,    such as benzyl.-   X, k and M^(k+) being as defined hereinbefore.

Special preference is given to the following compounds and compositions:

Com- Exam- pound R⁴¹ R⁴² R⁴³ (1/k) M^(K+) ple D-1  CH₂CH₂CH₂—O— CN CH₃K-1 1 CH(CH₃)₂ D-2  CH₂CH₂CH₂—O— CN CH₃ K-2 2 CH(CH₃)₂ D-3  H CN CH₃ K-13 D-4  CH₃ CN CH₃ K-1 4 D-5  CH₃ CN CH₃ K-2 5 D-6  C₂H₅ CN CH₃ K-1 6D-7  C₂H₅ CN CH₃ K-2 7 D-8  CH₂CH₂CH₂—O— CN CH₃ M-1 8 CH(CH₃)₂ D-9 CH₂CH₂CH₂—O— CN CH₃ M-2 9 CH(CH₃)₂ D-10 CH₂CH₂CH₂—O— CN CH₃ M-3 10CH(CH₃)₂ D-11 CH₂CH₂CH₂—O— CN CH₃ M-4 11 CH(CH₃)₂ D-12 phenyl CN CH₃ K-212 D-13 C₂H₅ C(O)NH₂ CH₃ K-2 13 D-14 CH₂CH₂CH₂—O— CN CH₃ K-3 14 CH(CH₃)₂D-15 CH₂CH₂CH₂—O— CN CH₃ K-2 15 CH(CH₃)₂ D-16 CH₂CH₂CH₂—O— CN CH₃ K-1 16CH(CH₃)₂ D-17 CH₂CH₂CH₂—O— CN CH₃ K-4 17 CH(CH₃)₂ D-48 H CN CH₃ K-3 48D-49 C₂H₅ CN CH₃ K-3 49 D-52 C₂H₅ H CH₃ K-2 52 D-53 H H COO⁻ K-2 53 D-54C₂H₅ C(O)NH₂ CH₃ K-2 54

Com- Exam- pound R⁴¹ R^(41 ′) (1/k) M^(K+) ple D-20 CH₃ C₂H₅ K-2 18 D-7 C₂H₅ C₂H₅ K-2 18 D-5  CH₃ CH₃ K-2 18 D-21 phenyl C₂H₅ K-2 19 D-7  C₂H₅C₂H₅ K-2 19 D-12 phenyl phenyl K-2 19 D-22 phenyl CH₂CH₂CH₂—O— K-2 20CH(CH₃)₂ D-15 CH₂CH₂CH₂—O— CH₂CH₂CH₂—O— K-2 20 CH(CH₃)₂ CH(CH₃)₂ D-12phenyl phenyl K-2 20 D-23 C₂H₅ CH₂CH₂CH₂—O— K-2 21 CH(CH₃)₂ D-15CH₂CH₂CH₂—O— CH₂CH₂CH₂—O— K-2 21 CH(CH₃)₂ CH(CH₃)₂ D-7  C₂H₅ C₂H₅ K-2 21

D-40,

D-41 and

D-42.

Com- pound R^(a) R^(a′) R^(b) R^(b′) (1/k) M^(K+) λ_(max) ε D-54 Ph PhPh Ph K-8 597.2 175936 D-55 CH₃ CH₃ CH₃ CH₃ K-8 594.4  62550 D-56 CH₃CH₃ CH₃ CH₃ K-3 594.7 148970 D-57 tBu tBu C₂H₅ C₂H₅ K-9 — — D-58 CH₃ CH₃CH₃ CH₃ K-9 — — D-59 tBu tBu C₂H₅ C₂H₅ K-8 597.2  95732 D-60 H H Ph PhK-8 602.9 148327 D-61 ¹⁾ ¹⁾ tBu tBu K-8 — — D-62 ¹⁾ ¹⁾ ¹⁾ ¹⁾ K-8 — —D-63 Ph Ph Ph Ph K-9 597.1 — D-64 ¹⁾ ¹⁾ H H K-8 593.4 — D-65 Ph Ph H HK-9 594.4 133022 D-66 Ph Ph H H K-2 594.2 142542 D-67 ¹⁾ ¹⁾ ¹⁾ ¹⁾ K-9 —— D-6B Ph n-Bu n-Bu Ph K-8 — — D-69 Ph n-Bu n-Bu Ph K-9 — —¹⁾—CH₂—CH═CH₂.

The oxonol dyes described above can be prepared in accordance with, orin analogy to, methods described in DE-A-2 012 050, DE-A-2 835 074, U.S.Pat. No. 3,681,345, U.S. Pat. No. 4,968,593, U.S. Pat. No. 6,225,024 andEP-A-0 833 314.

The recording layer may also comprise, instead of a single compound offormula (II), a mixture of such compounds with, for example, 2, 3, 4 or5 oxonol dyes according to the invention. The use of mixtures, forexample mixtures of isomers or homologues but also mixtures of differingstructures, can often result in an increase in solubility and/or areduction in the tendency to aggregate. Where appropriate, mixtures ofion-pair compounds may have differing anions, differing cations or bothdiffering anions and differing cations.

The oxonol dyes used in accordance with the invention have, incombination with the metal complexes of formula (I), a narrow absorptionband whose maximum is located at from 540 to 640 nm or in the rangelower than 450 nm. The use of metal complexes of formula (I) results,surprisingly, in a comparatively weak tendency of the oxonol dyes toaggregate in the solid sate so that the absorption curve remainsadvantageously narrow even in the solid state.

The compositions used in accordance with the invention, in the form of asolid film, as used in optical storage media, have, on thelonger-wavelength flank of the absorption band, a high refractive indexwhich reaches a peak value of from 2.0 to 3.0 in the range from 600 to700 nm and more than 1.9 in the range from 390 to 430 nm, so that amedium having high reflectivity as well as high sensitivity and goodplayback characteristics in the desired spectral range can be achieved.

The substrate, which functions as support for the layers appliedthereto, is advantageously semi-transparent (T≧10%) or, preferably,transparent (T≧90%). The support generally has a thickness of from 0.01to 10 mm, preferably from 0.1 to 5 mm.

The recording layer is located preferably between the transparentsubstrate and the reflecting layer. The thickness of the recording layeris from 10 to 1000 nm, preferably from 30 to 300 nm, especially from 60to 120 nm. The absorption of the recording layer is generally from 0.1to 1.0 at the absorption maximum. The layer thickness is very especiallyso selected in dependence upon the respective refractive indices in thenon-written state and in the written state at the reading wavelengththat, in the non-written state, constructive interference is obtainedbut, in the written state, destructive interference is obtained, or viceversa.

The reflecting layer, the thickness of which can be from 10 to 150 nm,preferably has high reflectivity (R≧45%, especially R≧60%), coupled withlow transparency (T≦10%). In further embodiments, for example in mediahaving a plurality of recording layers, the reflector layer may likewisebe semi-transparent, that is to say may have comparatively hightransparency (for example T≧50%) and low reflectivity (for exampleR≦45%).

The uppermost layer, for example the reflective layer or the recordinglayer, depending upon the layer structure, is advantageouslyadditionally provided with a protective layer having a thickness ofgenerally from 0.1 to 1000 μm, preferably from 0.1 to 50 μm andespecially from 0.5 to 15 μm. Such a protective layer can, if desired,serve also as adhesion promoter for a second substrate layer appliedthereto, which is preferably from 0.1 to 5 mm thick and consists of thesame material as the support substrate.

The reflectivity of the entire recording medium is preferably at least15%, especially at least 40% (for example 45% for DVD-R).

The main features of the recording layer according to the invention arethe very high initial reflectivity in the said wavelength range of thelaser diodes, which reflectivity can be modified with especially highsensitivity; the high refractive index; the narrow absorption band inthe solid state; the good uniformity of the script width at differentpulse durations; the good light-stability; and the good solubility innon-halogenated solvents, especially alcohols. The use of thecompositions according to the invention results in advantageouslyhomogeneous, amorphous and low-scatter recording layers having a highrefractive index, and the absorption edge is surprisingly especiallysteep even in the solid phase. Further advantages are highlight-stability in daylight and under laser radiation of low powerdensity with, at the same time, high sensitivity under laser radiationof high power density, uniform script width, high contrast, and alsogood thermal stability and storage stability.

At a relatively high recording speed, the results obtained aresurprisingly better than with previously known recording media. Themarks are more precisely defined relative to the surrounding medium andthermally induced deformations do not occur. The error rate (BLER or PISim 8) and the statistical variations in mark length (jitter) are alsolow both at normal and at relatively high recording speed, so thaterror-free recording and playback can be achieved over a large speedrange. The advantages are obtained in the entire range from 600 to 700nm (preferably from 630 to 690 nm), but are especially pronounced at640-680 nm, more especially at from 650 to 670 nm, very especially at658*±5 nm. Suitable substrates are, for example, glass, minerals,ceramics and thermosetting or thermoplastic plastics. Preferred supportsare glass and homo- or co-polymeric plastics. Suitable plastics are, forexample, thermoplastic polycarbonates, polyamides, polyesters,polyacrylates and polymethacrylates, polyurethanes, polyolefins,polyvinyl chloride, polyvinylidene fluoride, polyimides, thermosettingpolyesters and epoxy resins. The substrate can be in pure form or mayalso comprise customary additives, for example UV absorbers or dyes, asproposed, for example, in JP 04/167239 as light-stabilisers for therecording layer. In the latter case it may be advantageous for the dyeadded to the support substrate to have an absorption maximumhypsochromically shifted relative to the dye of the recording layer byat least 10 nm, preferably by at least 20 nm.

The substrate is advantageously transparent over at least a portion ofthe range from 600 to 700 nm so that it is permeable to at least 90% ofthe incident light of the writing or readout wavelength. The substratehas preferably on the coating side a spiral guide groove having a groovedepth of from 50 to 500 nm, a groove width of from 0.2 to 0.8 μm and atrack spacing between two turns of from 0.4 to 1.6 μm, especially havinga groove depth of from 100 to 200 nm, a groove width of 0.3 μm and aspacing between two turns of from 0.6 to 0.8 μm. The compositionsaccording to the invention are therefore suitable especiallyadvantageously for use in DVD media having the currently customary pitwidth of 0.4 μm and track spacing of 0.74 μm.

For a further increase in stability it is also possible, if desired, toadd known stabilisers in customary amounts, such as, for example, anickel dithiolate described in JP 04/025 493 as light-stabiliser.

The recording layer comprises a compound of formula (II) or a mixture ofsuch compounds advantageously in an amount sufficient to have asubstantial influence on the refractive index. Such an amount isgenerally at least 30% by weight, preferably at least 60% by weight,especially at least 80% by weight.

Suitable concentrations of metal complex compound(s) of formula (I) aregenerally from 1 to 1000% by weight, preferably from 30 to 60% byweight, based on the oxonol compound(s) of formula (II).

The recording media may comprise customary additives, for examplefilm-formers, further customary constituents, such as, for example,other chromophores (for example those having an absorption maximum atfrom 300 to 1000 nm), UV absorbers and/or other stabilisers, quenchers,such as, for example, fluorescence quenchers, melting-point depressantsand decomposition accelerators.

When the recording layer comprises further chromophores, suchchromophores may in principle be any dyes that can be decomposed ormodified by the laser radiation during the recording, or they may beinert towards the laser radiation. When the further chromophores aredecomposed or modified by the laser radiation, this can take placedirectly by absorption of the laser radiation or can be inducedindirectly by the decomposition of the compounds of formula (I) or (II)according to the invention.

When further chromophores having optical properties that conform as faras possible to those of the oxonol dyes are used, this should preferablybe the case in the range of the longest-wavelength absorption flank.Preferably the wavelengths of the inversion points of the furtherchromophores and of the oxonol dyes are a maximum of 20 nm, especially amaximum of 10 nm, apart. In that case the further chromophores and theoxonol dyes should exhibit similar behaviour in respect of the laserradiation so that it is possible to use as further chromophores knownrecording agents the action of which is synergistically enhanced by thecompounds of formula (I) or (II).

When further chromophores or coloured stabilisers having opticalproperties that are as different as possible from those of compounds offormula (I) or (II) are used, they advantageously have an absorptionmaximum that is hypsochromically or bathochromically shifted relative tothe dye of formula (I) or (II). In that case the absorption maxima arepreferably at least 50 nm, especially at least 100 nm, apart. Examplesthereof are UV absorbers that are hypsochromic to the dye of formula (I)or (II), or coloured stabilisers that are bathochromic to the dye offormula (I) or (II) and have absorption maxima lying, for example, inthe NIR or IR range. Other dyes can also be added for the purpose ofcolour-coded identification, colour-masking (“diamond dyes”) orenhancing the aesthetic appearance of the recording layer. In thosecases, the further chromophores or coloured stabilisers should exhibitbehaviour that is preferably as inert as possible in respect of lightand laser radiation.

When chromophores or coloured stabilisers are used for other purposes,the amount thereof should preferably be so low that their contributionto the total absorption of the recording layer in the range from 600 to700 nm is at most 20%, preferably at most 10%. In such a case, theamount of additional dye or stabiliser is advantageously at most 50% byweight, preferably at most 10% by weight, based on the recording layer.

Further chromophores that can be used in the recording layer in additionto the oxonol compounds are, for example, cyanines and cyanine metalcomplex salts (U.S. Pat. No. 5,958,650), styryl compounds (U.S. Pat. No.6,103,331), azo dyes and azo metal complexes (JP-A-11/028865),phthalocyanines (EP-A-232 427, EP-A-337 209, EP-A-373 643, EP-A-463 550,EP-A-492 508, EP-A-509 423, EP-A-511 590, EP-A-513 370, EP-A-514 799,EP-A-518 213, EP-A-519 419, EP-A-519423, EP-A-575 816, EP-A-600 427,EP-A-676 751, EP-A-712 904, WO-98/14520, WO-00/09522, CH-693/01),porphyrins and azaporphyrins (EP-A-822 546, U.S. Pat. No. 5,998,093),dipyrromethene dyes and metal chelate compounds thereof (EP-A-822 544,EP-A-903 733), xanthene dyes and metal complex salts thereof (U.S. Pat.No. 5,851,621) or quadratic acid compounds (EP-A-568 877), alsooxazines, dioxazines, diazastyryls, formazans, anthraquinones orphenothiazines.

Besides the metal complexes of formula I, further stabilisers orfluorescence quenchers may be used, for example metal complexes ofnitrogen- or sulfur-containing enolates, phenolates, bisphenolates,thiolates, bisthiolates or of azo, azomethine or formazan dyes, e.g.®Irgalan Bordeaux EL (Ciba Spezialitätenchemie AG) or similar compounds,hindered phenols and derivatives thereof (where appropriate also asanions X⁻), e.g. ®Cibafast AO (Ciba Spezialitätenchemie AG),hydroxyphenyl-triazoles, -triazines or other UV absorbers, e.g.®Cibafast W or ®Cibafast P (Ciba Spezialitätenchemie AG) or hinderedamines (TEMPO or HALS, also in the form of nitroxides or NOR-HALS, whereappropriate also as anions X⁻). Many such structures are known, some ofthem also in connection with optical recording media, for example fromU.S. Pat. No. 5,219,707, JP-A-06/199045, JP-A-07/76169 orJP-A-07/262,604.

The recording medium according to the invention, in addition tocomprising the compounds of formula (I) or (II), may additionallycomprise salts, for example ammonium chloride, pentadecylammoniumchloride, sodium chloride, sodium sulfate, sodium methyl sulfonate orsodium methyl sulfate, the ions of which may originate, for example,from the components used. The additional salts, if present, may bepresent preferably in amounts of up to 20% by weight, based on the totalweight of the recording layer.

Reflecting materials suitable for the reflective layer includeespecially metals, which provide good reflection of the laser radiationused for recording and playback, for example the metals of Main GroupsIII, IV and V and of the Sub-Groups of the Periodic Table of theElements. Al, In, Sn, Pb, Sb, Bi, Cu, Ag, Au, Zn, Cd, Hg, Sc, Y, La, Ti,Zr, Hf, V, Nb, Ta, Cr, Mo, W, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Ce,Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and alloysthereof are especially suitable. Special preference is given to areflective layer of aluminium, silver, copper, gold or an alloy thereof,on account of their high reflectivity and ease of production.

Materials suitable for the protective layer include chiefly plastics,which are applied in a thin layer to the support or to the uppermostlayer either directly or with the aid of adhesive layers. It isadvantageous to select mechanically and thermally stable plastics havinggood surface properties, which may be modified further, for examplewritten. The plastics may be thermosetting plastics or thermoplasticplastics. Preference is given to radiation-curable (for example by meansof UV radiation) protective layers, which are particularly simple andeconomical to produce. A wide variety of radiation-curable materials areknown. Examples of radiation-curable monomers and oligomers areacrylates and methacrylates of diols, triols and tetrols, polyimides ofaromatic tetracarboxylic acids and aromatic diamines having C₁-C₄alkylgroups in at least two-ortho-positions to the amino groups, andoligomers with dialkylmaleimidyl groups, e.g. dimethylmaleimidyl groups.

The recording media according to the invention may have additionallayers, for example interference layers. It is also possible toconstruct recording media having a plurality of (for example two)recording layers. The structure and the use of such materials are knownto the person skilled in the art. Preference is given to interferencelayers that are arranged between the recording layer and the reflectinglayer and/or between the recording layer and the substrate and consistof a dielectric material, for example as described in EP-A-353 393 ofTiO₂, Si₃N₄, ZnS or silicone resins.

The recording media according to the invention can be produced byprocesses known per se, it being possible for various methods of coatingto be employed depending upon the materials used and their function.

Suitable coating methods are, for example, immersion, pouring,brush-coating, blade-application and spin-coating, as well asvapour-deposition methods carried out under a high vacuum. When, forexample, pouring methods are used, solutions in organic solvents aregenerally employed. Suitable coating methods and solvents are described,for example, in EP-A-401 791.

The recording layer is applied preferably by spin-coating with a dyesolution, solvents that have proved satisfactory being especiallyalcohols, such as, for example, 2-methoxyethanol, n-propanol,isopropanol, isobutanol, n-butanol, amyl alcohol or 3-methyl-1-butanoland mixtures thereof. Ethers (dibutyl ether), ketones(2,6-dimethyl-4-heptanone, 5-methyl-2-hexanone) or saturated orunsaturated hydrocarbons (toluene, xylene) can also be used, for examplein the form of mixtures (e.g. dibutyl ether/2,6-dimethyl-4-heptanone) ormixed components.

The invention therefore relates also to a method of producing an opticalrecording medium, wherein a solution of a compound of formula (I) in anon-halogenated organic solvent is applied to a substrate havingdepressions. The application is preferably carried out by spin-coating.

The application of the metallic reflective layer is preferably effectedby sputtering, vapour-deposition in vacuo or by chemical vapourdeposition (CVD). The sputtering technique is especially preferred forthe application of the metallic reflective layer on account of the highdegree of adhesion to the support. Such techniques are known and aredescribed in specialist literature (e.g. J. L. Vossen and W. Kern, “ThinFilm Processes”, Academic Press, 1978).

The structure of the recording medium according to the invention isgoverned primarily by the readout method; known function principlesinclude the measurement of the change in transmission or, preferably,reflection, but it is also known to measure the fluorescence instead ofthe transmission or reflection.

When the recording medium operates on the basis of a change inreflection, the recording medium may be structured, for example, asfollows: transparent support/recording layer (optionallymultilayered)/reflective layer and, if expedient, protective layer (notnecessarily transparent); or support (not necessarilytransparent)/reflective layer/recording layer and, if expedient,transparent protective layer. In the first case, the light is incidentfrom the support side, whereas in the latter case the radiation isincident from the recording layer side or, where applicable, from theprotective layer side. In both cases the light detector is located onthe same side as the light source. The first-mentioned structure of therecording medium is generally preferred for DVD-R, the latter-mentionedstructure (inverse structure) is desirable especially for recordingsystems in the blue-violet range (DVR; EP-A-822 546 and EP-A-1 103 962).

When the recording medium operates on the principle of a change in lighttransmission, the following structure, for example, comes intoconsideration: transparent support/recording layer (optionallymultilayered) and, if expedient, transparent protective layer. The lightfor recording and for readout can be incident either from the supportside or from the recording layer side or, where applicable, from theprotective layer side, the light detector in this case always beinglocated on the opposite side.

Suitable lasers are those having a wavelength of 600-700 nm, for examplecommercially available lasers having a wavelength of 602, 612, 633, 635,647, 650, 670 or 680 nm, especially semi-conductor lasers, such asGaAsAl, InGaAlP or GaAs laser diodes having a wavelength especially ofabout 635, 650 or 658 nm, with a wavelength of from 380 to 420 nm,especially 405±5 nm, for the blue-violet range. The recording isgenerally effected point for point, by modulating the laser inaccordance with the mark lengths and focussing its radiation onto therecording layer.

The method according to the invention allows the storage of informationwith great reliability and stability, distinguished by very goodmechanical and thermal stability and by high light-stability and bysharp boundary zones of the pits. Special advantages include the highcontrast, the low jitter and the surprisingly high signal/noise ratio,so that problem-free readout is achieved.

The readout of information is carried out according to methods known perse by registering the change in absorption or reflection using laserradiation, for example as described in “CD-Player und R-DAT Recorder”(Claus Biaesch-Wiepke, Vogel Buchverlag, Würzburg 1992).

The information-containing medium according to the invention isespecially an optical information material of the WORM type. It can beused, for example, as a playable DVD (digital versatile disk), asstorage material for a computer or as an identification and securitycard or for the production of diffractive optical elements, for exampleholograms.

The invention accordingly relates also to a method for the opticalrecording, storage and playback of information, wherein a recordingmedium according to the invention is used. The recording and theplayback advantageously take place in a wavelength range of from 600 to700 nm, or less than 450 nm.

The compositions according to the invention are, moreover, suitable forthe production of printing inks having excellent application propertiesfor various uses such as intaglio/flexographic printing, sheet offsetprinting and sheet-metal printing, and for the production of colourfilters that have an advantageously narrow absorption curve. Theinvention accordingly relates also to a printing ink or colour filter(optical filter) comprising a composition according to the invention,wherein oxonols are particularly preferred, wherein M^(k+) is a hydrogencation. The invention relates especially to an optical filter comprisinga support layer and a filter layer, wherein the filter layer comprises acomposition according to the invention. The optical filters canthemselves be used for example in electro-optical systems such as TVscreens, liquid crystal displays, charge coupled devices, plasmadisplays or electroluminescent displays and the like.

The filter layer contains from 1 to 75% by weight, preferably from 5 to50% by weight, most preferably from 25 to 40% by weight, of thecomposition according to the invention, based on the total weight of thefilter layer, dispersed in a high-molecular-weight organic material. Thesupport layer is preferably substantially colourless (T≧95% in theentire visible range from 400 to 700 nm). Further details relating tothe production of colour filters and the high-molecular-weight materialsused in the production of colour filters are described, for example, inHigh-Technology Applications of Organic Colorants, Peter Gregory, PlenumPress, New York and London 1991, p. 15 to 25, WO01/04215 and WO02/10288.Optical filters having an absorption maximum in the range from 560 to620 nm are, for example, suitable as very-narrow-band optical filtersfor plasma displays (see, for example, EP-A-1 124 144).

The printing inks of the invention contain the compositions of theinvention judiciously in a concentration of from 0.01 to 40% by weight,preferably from 1 to 25% by weight, with particular preference from 5 to10% by weight, based on the overall weight of the printing ink, and maybe used, for example, for gravure printing, flexographic printing,screen printing, offset printing, or continuous or dropwise inkjetprinting on paper, board, metal, wood, leather, plastic or textiles, orelse in special applications in accordance with formulations which aregeneral knowledge, for example in publishing, packaging or freight, inlogistics, in advertising, in security printing or else in the officesector for ballpoint pens, felt-tip pens, fibre-tip pens, inking pads,ink ribbons or inkjet printer cartridges.

The Examples that follow illustrate the invention. Unless otherwiseindicated, figures in percent and in parts are percent by weight andparts by weight, respectively. Unless otherwise indicated, λ_(max) and εwere measured in DMF (dimethylformamide).

In the Examples hereinbelow, the ammonium salt of Primene 81R® (Rohm &Haas Company, mixture of C₁₂₋₁₄amine isomers) is shown in idealisedform:

EXAMPLE 1

100 parts ofN-(3-isopropoxy-propyl)-3-cyano-4-methyl-6-hydroxy-2-pyridone arestirred with 33 parts of 1,1,3,3-tetramethoxy-propane in 120 parts ofpyridine for 2 hours at 110° C. under inert gas. After cooling to roomtemperature, the reaction product is precipitated out, and the solidmaterial is separated off by means of suction filtration and washed, insuccession, with 25 parts of pyridine and 200 parts of water. The targetcompound of the formula indicated below is dried at 90° C. in vacuo (120mbar) (yield: 63%). 53 parts of the crude product are stirred in 300parts of methanol for 10 minutes at 70° C. After cooling, the residue isseparated off by means of suction filtration, washed with 100 parts ofmethanol and dried at 90° C. in vacuo (yield: 66%).

EXAMPLE 2

57 parts of the product obtained in Example 1 are stirred in 300 partsof methanol at room temperature, and 11 parts of Primene 81R® (Rohm &Haas Company, mixture of C₁₂₋₁₄amine isomers) are added. The solution istreated with active carbon and the filtrate is concentrated. The residueis dried at 90° C. A blue product of the formula indicated below isobtained (yield: 56%).

The compounds D-3 to D-17 indicated below can be obtained in analogy tothe methods described in Examples 1 and 2:

Exam- Com- (1/k) ple pound R⁴¹ R⁴² R⁴³ M^(K+) λ_(max) ε 3 D-3 H CN CH₃K-1 603.5 198600 4 D-4 CH₃ CN CH₃ K-1 601.5 116500 5 D-5 CH₃ CN CH₃ K-2601.8 200300 6 D-6 C₂H₅ CN CH₃ K-1 602.6 187500 7 D-7 C₂H₅ CN CH₃ K-2603 194300 8 D-8 ¹⁾ CN CH₃ M-1 9 D-9 ¹⁾ CN CH₃ M-2 10 D-10 ¹⁾ CN CH₃ M-311 D-11 ¹⁾ CN CH₃ M-4 12 D12 ²⁾ phenyl CN CH₃ K-2 605.2 138200 13 D-13C₂H₅ C(O)NH₂ CH₃ K-2 589 14 D-14²⁾ ¹⁾ CN CH₃ K-3 602.9 176000 15 D-15 ¹⁾CN CH₃ K-2 603.5 199500 16 D-16 ¹⁾ CN CH₃ K-1 17 D-17 ¹⁾ CN CH₃ K-4 48D-48²⁾ H CN CH₃ K-3 603.3 214200 49 D-49²⁾ C₂H₅ CN CH₃ K-3 602.7 217 60052 D-52³⁾ C₂H₅ H CH₃ K-2 53 D-52³⁾ H H COO⁻ K-2 54 D-52³⁾ C₂H₅ C(O)NH₂CH₃ K-2¹⁾CH₂CH₂CH₂—O—CH(CH₃)₂.²⁾These compounds are obtained in accordance with, or in analogy to, themethod described in Example 12.³⁾These compounds are obtained in accordance with, or in analogy to, themethod described in Example 53.

EXAMPLE 12

22.62 g (0.1 mol) of N-phenyl-3-cyano-4-methyl-6-hydroxy-2-pyridonetogether with 8.21 g (0.05 mol) of tetramethoxypropane, 9.27 g (0.05mol) of Primene 81R® in 200 ml of n-butanol are boiled under reflux for18 hours. The suspension is filtered whilst hot and then cooled. Theblue product that precipitated out is filtered off under suction, washedwith ethanol and dried at 80° C. in vacuo (120 mbar).

The compounds D-20 to D-31 indicated below are obtained in analogy tothe methods described in Examples 1, 2 and 12, with a mixture of twodifferent starting materials in a ratio of 50:50 being used instead of asingle N-(3-isopropoxy-propyl)-3-cyano-4-methyl-6-hydroxy-2-pyridonestarting material:

Exam- Com- ple pound R⁴¹ R^(41′) (1/k) M^(K+) 18 D-20 CH₃ C₂H₅ K-2¹⁾ 18D-7  C₂H₅ C₂H₅ K-2¹⁾ 18 D-5  CH₃ CH₃ K-2¹⁾ 19 D-21 phenyl C₂H₅ K-2²⁾ 19D-7  C₂H₅ C₂H₅ K-2²⁾ 19 D-12 phenyl phenyl K-2²⁾ 20 D-22 phenylCH₂CH₂CH₂—O— K-2³⁾ CH(CH₃)₂ 20 D-15 CH₂CH₂CH₂—O— CH₂CH₂CH₂—O— K-2³⁾CH(CH₃)₂ CH(CH₃)₂ 20 D-12 phenyl phenyl K-2³⁾ 21 D-23 C₂H₅ CH₂CH₂CH₂—O—K-2⁴⁾ CH(CH₃)₂ 21 D-15 CH₂CH₂CH₂—O— CH₂CH₂CH₂—O— K-2⁴⁾ CH(CH₃)₂ CH(CH₃)₂21 D-7  C₂H₅ C₂H₅ K-2⁴⁾¹⁾The mixture of D20:D7:D5 obtained in Example 18 exhibits a λ_(max) of601.9 nm.²⁾The mixture of D21:D7:D12 obtained in Example 19 exhibits a λ_(max) of603.3 nm.³⁾The mixture of D22:D15:D12 obtained in Example 20 exhibits a λ_(max)of 603.9 nm.⁴⁾The mixture of D23:D15:D7 obtained in Example 21 exhibits a λ_(max) of602.8 nm.

EXAMPLE 22

EXAMPLE 23

EXAMPLE 24

EXAMPLE 25

246 mg of the pyridinium salt of the oxonol dye (≅D-16) indicated beloware dissolved in 40 ml of acetone at room temperature. 256 mg of theperchlorate salt of the cyanine dye indicated below are dissolved in 25ml of acetone and added dropwise to the solution of the oxonol dye. Thesolution is stirred for half an hour at room temperature, filtered andconcentrated by evaporation. The residue is taken up in 18 ml ofmethylene chloride, washed three times with 15 ml of water andconcentrated by evaporation. 466.1 mg of the ion pair indicated beloware obtained.

EXAMPLE 26

61.5 mg of the pyridinium salt of the oxonol dye indicated below (≅D-16)are dissolved in 25 ml of ethanol at 30-400° C. 58 mg of the iodide saltof the cyanine dye indicated below are dissolved in 20 ml of ethanol andadded dropwise to the solution of the oxonol dye. The solution isstirred for half an hour at room temperature, filtered and concentratedby evaporation. The residue is taken up in 4 ml of deionised water,treated with ultrasound for half an hour, filtered and dried. 102.1 mgof the ion pair indicated below are obtained.

EXAMPLE 27

100 mg of D-50 obtained in Example 25 are dissolved in 25 ml of methanolat room temperature. 30.6 mg of M-5 are dissolved in 80 ml of methanolat from 45 to 50° C. and added to the solution of D-50. The solution isstirred for half an hour at room temperature, filtered and concentratedby evaporation. The residue is taken up in 4 ml of deionised water,treated with ultrasound for half an hour, filtered and dried. 130.1 mgof a mixture of D-50 and M-5 are obtained.

EXAMPLE 28

A solution of 3 parts of ethylenediamine in 20 parts of ethanol is addedto a solution of 12 parts of salicylaldehyde in 100 parts of ethanol andthe resulting mixture is heated until a solution is obtained. 9 parts ofcopper acetate in water are added, a grey precipitate being obtained.The mixture is cooled and filtered, a greenish solid of the followingformula being obtained:

EXAMPLE 53

15.4 g (0.1 mol) of citrazinic acid together with 8.16 g (0.05 mol) oftetramethoxypropane and 15 ml of hydrochloric acid (conc.) are suspendedin 100 ml of 2-ethoxyethanol and boiled under reflux for 17 hours. Aftercooling, the precipitate is filtered off under suction, washed withmethanol and dried at 80° C. in vacuo (120 mbar). 7.37 g of blue productare obtained, which is converted to D-53 using Primene 81R®.

The complexes indicated in Table 2 below can be obtained in analogy tothe method described in Example 28. TABLE 2

Ex. Cpd. R⁵¹ R⁵² R⁵³ R⁵⁴ R⁶¹ R⁶² R⁶³ R⁵⁴ R¹ R⁴ R² R³ R²′ R³′ Me 29 M-1 HH H H H H ⁺N(CH₃)₃Y⁻ H CH₃ H H CH₃ H CH₃ Cu Y⁻ 30 M-2 H H ⁺N(CH₃)₃Y⁻ H HH ⁺N(CH₃)₃Y⁻ H H H H H H H Cu 2Y⁻ 31 M-3 H H ⁺N(CH₃)₃Y⁻ H H H ⁺N(CH₃)₃Y⁻H H H ¹⁾ ¹⁾ H H Cu 2Y⁻ 32 M-4 H H OCH₂CH₂— H H H OCH₂OH₂— H H H H H H HCu 2Y⁻ ⁺N(CH₃)₃Y⁻ ⁺N(CH₃)₃Y⁻ 28 M-5 H H H H H H H H H H H H H H Cu 33M-6 H H H CH₃ H H H CH₃ H H H H H H Cu 34 M-7 H H H OCH₃ H H H OCH₃ H HH H H H Cu 35 M-8 H H OC₁₂H₂₅ H H H OC₁₂H₂₅ H H H H H H H Cu 36 M-9 H HOC₂H₄OCH₃ H H H OC₂H₄OCH₃ H H H H H H H Cu 37 M-10 H H OC₂H₄OC₂H₄OC₂H₅ HH H OC₂H₄OC₂H₄OC₂H₅ H H H H H H H Cu 38 M-11 H H O-tert-C₄H₉ H H HO-tert-C₄H₉ H H H H H H H Cu 39 M-12 H H H H H H H H C₂H₅ C₂H₅ H H H HCu 40 M-13 CH₃ H H CH₃ CH₃ H H CH₃ H H H H H H Cu 41 M-14 H H H H H H HH H H ¹⁾ ¹⁾ H H Cu 42 M-15 H H H H H H H H H H ¹⁾ ¹⁾ H H Co 43 M-16 Htert- H tert- H tert- H tert- H H ¹⁾ ¹⁾ H H Ni C₄H₉ C₄H₉ C₄H₉ C₄H₉ 44M-17 H H H H H H H H H H ¹⁾ ¹⁾ H H Ni 45 M-18 H H NCH₃)₂ H H H N(CH₃)₂ HH H ¹⁾ ¹⁾ H H Ni 46 M-19 H H OP(O)OC₂H₅)₂ H H H OP(O)OC₂H₅)₂ H H H H H HH Cu 47 M-20 H SO₃- H H H SO₃- H H H H H H H H Cu Y1+ Y1+ 48 M-21 H HO-tert-C₄H₉ H H H O-tert-C₄H₉ H H H ²⁾ ²⁾ CN CN Ni 49 M-22 H H H H H H HH H H ³⁾ ³⁾ ³⁾ ³⁾ Ni 50 M-23 ⁴⁾ ⁴⁾ H ⁵⁾ ⁴⁾ ⁴⁾ H ⁵⁾ H H ²⁾ ²⁾ CN CN Ni′¹⁾R² and R³ together form a cyclohexane ring; ²⁾R² and R³ together forma double bond; ³⁾R², R^(2′), R³, and R^(3′) together form a phenyl ring;⁴⁾R⁵¹ and R⁵² togetherd, and/or R⁶¹ and R⁶² together, form a phenylring; ⁵⁾—C(O)OCH₂CH₂OCH₂CH₂OH.

EXAMPLE 54

2.80 g N,N-diphenylbarbituric acid and 1.43 g mono-hydrochloride salt ofN-[5-(phenylamino)-2,4-pentadienylidenelaniline are dissolved in 40 mlacetone and cooled in an ice-bath to 5° C. Then 3 ml triethylamine areadded and the mixture is stirred for 3 h. The violet solution isconcentrated by evaporation, the residue is washed with diethyl etherand water and dried at 45° C. 3.14 g of the ion pair D-54 indicatedbelow are obtained.

The compounds D-55 to D-70 indicated below can be obtained in analogy tothe method described in Examples 54:

D-70 (λ_(max) = 552 nm)

Ex- am- Com ple pound R^(a) R^(a′) R^(b) R^(b′) (1/k) ^(MK+) λ_(max) ε54 D-54 Ph Ph Ph Ph K-8 597.2 175936 55 D-55 CH₃ CH₃ CH₃ CH₃ K-8 594.4 62550 56 D-56 CH₃ CH₃ CH₃ CH₃ K-3 594.7 148970 57 D-57 tBu tBu C₂H₅C₂H₅ K-9 — — 58 D-58 CH₃ CH₃ CH₃ CH₃ K-9 — — 59 D-59 tBu tBu C₂H5 C₂H₅K-8 597.2  95732 60 D-60 H H Ph Ph K-8 602.9 148327 61 D-61 ¹⁾ ¹⁾ tButBu K-8 — — 62 D-62 ¹⁾ ¹⁾ ¹⁾ ¹⁾ K-8 — — 63 D-63 Ph Ph Ph Ph K-9 597.1 —64 D-64 ¹⁾ ¹⁾ H H K-8 593.4 — 65 D-65 Ph Ph H H K-9 594.4 133022 66 D-66Ph Ph H H K-2 594.2 142542 67 D-67 ¹⁾ ¹⁾ ¹⁾ ¹⁾ K-9 — — 68 D-68 Ph n-Bun-Bu Ph K-8 — — 69 D-69 Ph n-Bu n-Bu Ph K-9 — —¹⁾—CH₂—CH═CH₂.

APPLICATION EXAMPLE 1

1.5% by weight of an equimolar mixture of M-5 and D-2 according toExample 2 are dissolved in 1-propanol and the solution was filteredthrough a Teflon filter having a pore size of 0.2 μm and applied, by thespin-coating method, at 1000 rev/min to the surface of a 0.6 mm-thick,grooved polycarbonate disc (groove depth 170 nm, groove width 350 nm,track spacing 0.74 μm) of diameter 120 mm. Excess solution is spun offby increasing the rotational speed. On evaporation of the solvent, thedye remained behind in the form of a uniform, amorphous solid layer.After drying in a circulating-air oven at 70° C. (10 minutes), the solidlayer exhibits an absorption of 0.50 at 623 nm. In a vacuum coatingapparatus (Twister™, Balzers Unaxis), a 70 nm-thick layer of silver isthen applied, by atomisation, to the recording layer. Then a 6 μm-thickprotective layer of a UV-curable photopolymer (650-020, DSM) was appliedthereto by means of spin-coating. The recording support exhibited areflectivity of 48% at 658 nm.

Using a commercial test apparatus (DVDT-R™, Expert Magnetics), marks arewritten into the active layer at a speed of 3.5 m/sec and a laser powerof 9.5 mW using a laser diode of wavelength 658 nm. The dynamicparameters are then determined using the same test apparatus, with goodmeasurement values being obtained: DTC jitter=9.0%; R14H=47%;|14/14H=0.6.

APPLICATION EXAMPLE 2

0.2% by weight of compound D-7 according to Example 7 are dissolved in aplasticiser, in one instance together with, and in one instance without,an equimolar addition of compound M-5 of Example 28, and thenincorporated at 160° C. into a PVC film. The absorption spectrum of thetwo films is measured using a commercial UV/VIS spectrophotometer(Carey). The half-value width measured at 580 nm was 65 nm in the caseof the filter comprising the aggregated form (without the addition) and,in the case of the disaggregated form, is 24.5 nm at 613 nm.

APPLICATION EXAMPLE 3

83.3 g of zircon ceramic beads, 2.8 g of an equimolar mixture of M-5 andD-2, 0.28 g of Solsperse®5000, 4.10 g of Disperbyk® 161 (dispersant/BYKChemie: 30% solution of a high molecular mass block copolymer havinggroups with pigment affinity, in 1:6 n-butyl acetate/1-methoxy-2-propylacetate) and 14.62 g of propylene glycol monomethyl ether acetate (MPA,CAS Reg. N° 108-65-6) in a 100 ml glass vessel are stirred at 23° C.with a Dispermat at 1000 rpm for 10 minutes and at 3000 rpm for 180minutes. Following the addition of 4.01 g of acrylic polymer binder (35%solution in MPA) at room temperature, stirring is continued at 3000 rpmfor 30 minutes. After the beads have been separated off, the dispersionis diluted with an equal amount of MPA. A glass substrate (Coming Type1737-F) is coated with this dispersion in a paint spincoating apparatusand is spun at 1000 rpm for 30 s. The drying of the coat is carried outat 100° C. for 2 minutes and at 200° C. for 5 minutes on a hotplate. Thecoating thickness of the resultant bright violet/blue film is 0.4 μm.

APPLICATION EXAMPLE 4

0.01 mol of the oxonol D-71 are dissolved in 50 ml trifluoroacetic acid(TFA). 0.01 mol M-5 are also dissolved in TFA. Both solutions are mixedunder vigorous stirring. The obtained dark violet precipitate isfiltered off, washed with water until neutral, dried and sieved.

In a 100 ml glass vessel containing 83.3 g of zircon ceramic beads, 2.8g of the above product (D-71/M-5), 0.28 g of Solsperse® 5000, 4.10 g ofDisperbyk® 161 (dispersant/BYK Chemie: 30% solution of a high molecularmass block copolymer having groups with pigment affinity, in 1:6 n-butylacetate/1-methoxy-2-propyl acetate) and 14.62 g of propylene glycolmonomethyl ether acetate (MPA, CAS Reg. N° 108-65-6) are stirred at 23°C. with a Dispermat at 1000 rpm for 10 minutes and at 3000 rpm for 180minutes. Following the addition of 4.01 g of acrylic polymer binder (35%solution in MPA) at room temperature, stirring is continued at 3000 rpmfor 30 minutes. After the beads have been separated off, the dispersionis diluted with an equal amount of MPA. A glass substrate (Corning Type1737-F) is coated with this dispersion in a paint spin-coating apparatusand is spun at 1000 rpm for 30 s. The drying of the coat is carried outat 100° C. for 2 minutes and at 200° C. for 5 minutes on a hotplate. Thecoating thickness achieved is 0.4 μm. A bright violet/blue film isobtained.

If instead of 2.8 g of the product (D-71/M-5) 0.8-2.0 g epsilon CuPc(Atlantic Blue) and 0.8-2.0 g of the product (D-71/M-5) are used, abright blue film is obtained. With more oxonol the color becomes moreviolet.

Similar results are obtained, if instead of the oxonol D-71 the oxonolD-72 or D-73 is used.

1. A composition comprising at least one oxonol dye and at least onemetal complex of the following formula

wherein Me is a transition metal of Sub-Group 7, 8, 9, 10, 11 or 12, D¹and D² are each independently of the other a carbocyclic or heterocyclicring or ring system, which may be unsubstituted or substituted by one ormore groups R⁵ and R⁶, R⁵ and R⁶ being a halogen atom, an amino group,an alkylamino group, a dialkylamino group, a nitro group, a cyano group,a hydroxy group, an unsubstituted or substituted alkyl radical, anunsubstituted or substituted hydroxyalkyl radical, an unsubstituted orsubstituted alkoxy radical, an alkyl radical which is interrupted one ormore times by —O— or by —S— and which may be unsubstituted orsubstituted, an acyl radical, a phenyl group, an ester group, such as aphosphonic acid, phosphoric acid or carboxylic acid ester group, acarboxamide group, a sulfamide group, an ammonium group, a carboxylicacid, sulfonic acid, phosphonic acid or phosphoric acid group or a saltthereof, R¹ and R⁴ are each independently of the other a hydrogen atomor an unsubstituted or substituted alkyl radical, aryl radical oraralkyl radical, R², R^(2′), R³ and R^(3′) are each independently of theothers a hydrogen atom, a cyano group, an unsubstituted or substitutedalkyl radical, alkoxy radical, aryl radical or aralkyl radical, an estergroup, a carboxamide group, a sulfamide group, a trialkylammonium group,a carboxylic acid, sulfonic acid, phosphonic acid or phosphoric acidgroup or a salt thereof, or R² and R³ together, or R^(2′) and R^(3′)together, form a double bond, a cycloalkyl ring or a heterocyclic ring,or R², R^(2′), R³ and R³′ together form an aromatic carbocyclic orheterocyclic ring, R² and R³ together, and/or R^(2′) and R^(3′)together, form, each pair independently of the other, a carbonyl groupor a thiocarbonyl group, R⁷, R^(7′), R⁸ and R^(8′) are eachindependently of the others a hydrogen atom or an unsubstituted orsubstituted alkyl radical, aryl radical or aralkyl radical, or R⁷ and R⁷together, and/or R⁸ and R^(8′) together, form, each pair independentlyof the other, a carbonyl group or a thiocarbonyl group.
 2. A compositionaccording to claim 1, wherein the oxonol dye is a dye of formula

wherein A¹, A², B¹ and B² are in each case a substituent; Y¹ and Z¹ arein each case a group of atoms necessary for the formation of acarbocyclic or heterocyclic ring; E and G are in each case a group ofatoms necessary for the formation of a chain having conjugated doublebonds; X¹ is ═O, ═NR⁹ or ═C(CN)₂, R⁹ being a substituent; X is —O, —NR⁹or —C(CN)₂, R⁹ being a substituent; L is a methine group, which may besubstituted, or a group by means of which a polymethine group iscompleted, it being possible for 3, 5 or 7 methine groups to beconnected in order to form a chain having conjugated double bonds, whichchain may be substituted; M^(k+) is an organic or inorganic cation, itbeing possible for the metal complex of formula (I-1) or (I-2) to be thecation provided it carries one or more positive charge(s); x and y are 0or 1, and k is an integer from 1 to
 10. 3. A composition according toclaim 2, wherein M^(k+) is an ammonium cation or a cationic dye.
 4. Acomposition according to claim 3, wherein the cationic dye has anabsorption maximum in the range from 550 to 620 nm and/or less than 450nm.
 5. A composition according to claim 1, wherein the oxonol dye hasthe following general formula

wherein M^(k+) is an ammonium cation, k is an integer from 1 to 4,R^(a), R^(b), R^(a′) and R^(b′) are each independently of the other ahydrogen atom, a C₁₋₈alkyl radical, a hydroxy-C₁₋₈alkyl radical, aC₁₋₈alkenyl radical, an unsubstituted or C₁₋₄alkyl- orC₁₋₄alkoxy-substituted C₆₋₁₂aryl, or a C₇₋₁₂aralkyl radical, R⁴¹ andR^(41′) are each independently of the other a hydrogen atom, a C₁₋₄alkylradical, or a perfluoro-C₁₋₄alkyl radical, a hydroxy-C₁₋₄alkyl radical,or a C₁₋₈alkyl radical interrupted one or more times by —O—, a C₆₋₁₀arylradical, or a C₇₋₁₂aralkyl radical, R⁴² and R⁴²′ are each independentlyof the other a hydrogen atom, a cyano or carboxamide group, R⁴³ andR^(43′) are each independently of the other a hydrogen atom, acarboxylic acid group or a salt thereof or a C₁₋₄alkyl radical, R⁴⁴ andR^(44′) are each independently of the other a hydrogen atom, a C₁₋₄alkylradical, a C₆₋₁₂aryl or C₇₋₁₂aralkyl radical, or R⁴⁴ and R^(44′)together form a five-membered or six-membered ring, and R⁴⁵ is ahydrogen atom, a halogen atom, an unsubstituted or C₁₋₄alkyl- orC₁₋₄alkoxy-substituted C₆₋₁₂aryl radical, or a C₇₋₁₂aralkyl radical. 6.A composition according to claim 5, wherein M^(k+) is selected from thefollowing cations:

wherein R¹⁰, R^(10′) and R^(10″) are each independently of the others ahydrogen atom, a C₃₋₂₄cycloalkyl radical which is optionallysubstituted, R¹¹, R¹², R¹³ and R¹⁴ are a hydrogen atom, a straight-chainor branched C₁₋₃₆alkyl radical, which may be unsubstituted orsubstituted, a straight-chain or branched hydroxy-C₁₋₃₆alkyl radical,C₆₋₂₄aryl radical, or C₇₋₂₄aralkyl radical, or two of the radicals R¹¹,R¹², R¹³ and R¹⁴, together with the nitrogen atom to which they arebonded, form a five- or six-membered heterocyclic ring; or

wherein R⁶⁷ and R⁶⁸ are each independently of the other a substituent,R⁶⁵ and R⁶⁶ are each independently of the other a substituted orunsubstituted alkyl radical, a substituted or unsubstituted alkenylradical, a substituted or unsubstituted alkynyl radical, a substitutedor unsubstituted aralkyl radical, a substituted or unsubstituted arylradical or a substituted or unsubstituted heterocyclic radical, it beingpossible for the pairs R⁶⁷ and R⁶⁸, R⁶⁷ and R⁶⁵, R⁶⁸ and R⁶⁶, and R⁶⁵and R⁶⁶ to be connected to form a ring, and s and t are eachindependently of the other 0 or an integer from 1 to 4, provided thatwhen s and t have a value of 2 or more the groups R⁶⁷ and R⁶⁸ may be thesame or different; or of formula

wherein R⁶⁹ is a straight-chain or branched C₁₋₈alkyl radical, which isoptionally substituted;

wherein R²⁰¹, R²⁰² and R²⁰³ are each independently of the others ahydrogen atom, a straight-chain or branched C₁₋₃₆alkyl radical, whichmay be unsubstituted or substituted, a hydroxy-C₁₋₃₆alkyl radical, whichis unsubstituted or substituted by one or more C₁₋₄alkyl and/orC₁₋₄alkoxy radicals, a C₃₋₂₄cycloalkyl radical, C₆₋₂₄aryl radical, or aC₇₋₂₄aralkyl radical, or two of the radicals R²⁰¹, R²⁰² and R²⁰³,together with the nitrogen atom to which they are bonded, form a five-or six-membered heterocyclic ring, R²⁰⁴ is a hydrogen atom, a C₁₋₄alkylor C₁₋₄alkoxy radical, u and v are integers from 1 to 3, the sum of uand v being 3, 4 or 5, and X is a divalent connecting group or a metalcomplex of formula

wherein Me is Cu, Ni or Co, R⁵¹, R⁵², R⁵³, R⁵⁴, R⁶¹, R⁶², R⁶³ and R⁶⁴are a hydrogen atom, a chlorine atom, a bromine atom, a hydroxy group, aC₁₋₈alkyl radical which may be unsubstituted or substituted by a di- ortri-alkylammonium group, a C₁₋₁₆alkoxy radical which may beunsubstituted or substituted by a di- or tri-alkylammonium group, aC₁₋₈alkyl radical which is interrupted one or more times by —O— or by—S— and which may be unsubstituted or substituted by a di- ortri-alkylammonium group; an ester group, a carboxamide group, asulfamide group or a di- or tri-alkylammonium group, R¹ and R⁴ are eachindependently of the other a hydrogen atom or a C₁₋₈alkyl radical, R²,R^(2′), R³ and R^(3′) are a hydrogen atom, a cyano group or a C₁₋₈alkylradical or pairs of the radicals R² and R^(2′), R³ and R^(3′) togetherform a cyclohexane ring, at least one of the radicals R⁵¹, R⁵², R⁵³,R⁵⁴, R⁶¹, R⁶², R⁶³ and R⁶⁴ being a di- or tri-alkylammonium group orbeing substituted by a di- or tri-alkylammonium group, R⁷, R^(7′), R⁸and R⁸′ are each independently of the others a hydrogen atom or anunsubstituted or substituted C₁₋₈alkyl radical, a phenyl group or abenzyl group, or R⁷ and R⁷′ together, and/or R⁸ and R^(8′) together,form, each pair independently of the other, a carbonyl group or athiocarbonyl group.
 7. An optical recording medium comprising asubstrate and at least one recording layer, wherein the recording layercomprises a composition according to claim
 1. 8. (cancel).
 9. A methodof producing an optical recording medium, wherein a solution of acomposition according to claim 1 in a non-halogenated solvent is appliedto a substrate having depressions.
 10. An oxonol dye of formula (II-1)or (II-2) according to claim 2, wherein M^(k+) is a cationic dye.
 11. Amethod according to claim 9, wherein the organic solvent is an alcohol.12-13. (canceled).
 14. An optical filter comprising a support layer anda filter layer, wherein the filter layer comprises a composition of theinvention according to claim
 1. 15. A printing ink comprising acomposition of the invention according to claim
 1. 16. A compositionaccording to claim 6, wherein M^(k+) is selected from the followingcations:

wherein R¹⁰, R^(10′) and R^(10″) are each independently of the others ahydrogen atom, a C₃₋₂₄cycloalkyl radical which is unsubstituted orsubstituted by from one to three C₁₋₄alkyl radicals, or a straight-chainor branched C₁₋₂₄alkyl radical, R¹¹, R¹², R¹³ and R¹⁴ are a hydrogenatom, a straight-chain or branched C₁₋₃₆alkyl radical, which may beunsubstituted or substituted, a straight-chain or branchedhydroxy-C₁₋₃₆alkyl radical, C₆₋₂₄aryl radical, or C₇₋₂₄aralkyl radical,or two of the radicals R¹¹, R¹², R¹³ and R¹⁴, together with the nitrogenatom to which they are bonded, form a five- or six-membered heterocyclicring; or

wherein R⁶⁷ and R⁶⁸ are each independently of the other a substituent,R⁶⁵ and R⁶⁶ are each independently of the other a substituted orunsubstituted alkyl radical, a substituted or unsubstituted alkenylradical, a substituted or unsubstituted alkynyl radical, a substitutedor unsubstituted aralkyl radical, a substituted or unsubstituted arylradical or a substituted or unsubstituted heterocyclic radical, it beingpossible for the pairs R⁶⁷ and R⁶⁸, R⁶⁷ and R⁶⁵, R⁶⁸ and R⁶⁶, and R⁶⁵and R⁶⁶ to be connected to form a ring, and s and t are eachindependently of the other 0 or an integer from 1 to 4, provided thatwhen s and t have a value of 2 or more the groups R⁶⁷ and R⁶⁸ may be thesame or different; or of formula

wherein R⁶⁹ is a straight-chain or branched C₁₋₈alkyl radical, which maybe unsubstituted or substituted by a cyano group, a halogen atom or by aC₁₋₄alkoxy radical;

wherein R²⁰¹, R²⁰² and R²⁰³ are each independently of the others ahydrogen atom, a straight-chain or branched C₁₋₃₆alkyl radical, whichmay be unsubstituted or substituted, a hydroxy-C₁₋₃₆alkyl radical, whichis unsubstituted or substituted by one or more C₁₋₄alkyl and/orC₁₋₄alkoxy radicals, a C₃₋₂₄cycloalkyl radical, a C₆₋₂₄aryl radical, ora C₇₋₂₄aralkyl radical, or two of the radicals R²⁰¹, R²⁰² and R²⁰³,together with the nitrogen atom to which they are bonded, form a five-or six-membered heterocyclic ring, R²⁰⁴ is a hydrogen atom, a C₁₋₄alkylor C₁₋₄alkoxy radical, u and v are integers from 1 to 3, the sum of uand v being 3, 4 or 5, and X is a divalent connecting group which is aC₁₋₈alkylene radical which is unsubstituted or substituted by one ormore C₁₋₄alkyl and/or C₁₋₄alkoxy radicals, or a group

wherein R²⁰⁴ is as defined hereinbefore, Ar is a C₆₋₁₀aryl radical whichis unsubstituted or substituted by one or more C₁₋₄alkyl and/orC₁₋₄alkoxy radicals, Cy is a C₅₋₇cycloalkyl radical which isunsubstituted or substituted by one or more C₁₋₄alkyl and/or C₁₋₄alkoxyradicals, and t is an integer from 0 to 4; or a metal complex of formula

wherein Me is Cu, Ni or Co, R⁵¹, R⁵², R⁵³, R⁵⁴, R⁶¹ R⁶², R⁶³ and R⁶⁴ area hydrogen atom, a chlorine atom, a bromine atom, a hydroxy group, aC₁₋₈alkyl radical which may be unsubstituted or substituted by a di- ortri-alkylammonium group, a C₁₋₁₆alkoxy radical which may beunsubstituted or substituted by a di- or tri-alkylammonium group, aC₁₋₈alkyl radical which is interrupted one or more times by —O— or by—S— and which may be unsubstituted or substituted by a di- ortri-alkylammonium group; an ester group, a carboxamide group, asulfamide group or a di- or tri-alkylammonium group, R¹ and R⁴ are eachindependently of the other a hydrogen atom or a C₁₋₈alkyl radical, R²,R^(2′), R³ and R^(3′) are a hydrogen atom, a cyano group or a C₁₋₈alkylradical or pairs of the radicals R² and R^(2′), R³ and R^(3′) togetherform a cyclohexane ring, at least one of the radicals R⁵¹, R⁵², R⁵³,R⁵⁴, R⁶¹, R⁶², R⁶³ and R⁶⁴ being a di- or tri-alkylammonium group orbeing substituted by a di- or tri-alkylammonium group, R⁷, R^(7′), R⁸and R^(8′) are each independently of the others a hydrogen atom or anunsubstituted or substituted C₁₋₈alkyl radical, a phenyl group or abenzyl group, or R⁷ and R^(7′) together, and/or R⁸ and R^(8′) together,form, each pair independently of the other, a carbonyl group or athiocarbonyl group.
 17. A composition according to claim 6, whereinM^(k+) is the cation:

wherein R⁶⁷ and R⁶⁸ are each independently of the other a substituent,R⁶⁵ and R⁶⁶ are each independently of the other a substituted orunsubstituted alkyl radical, a substituted or unsubstituted alkenylradical, a substituted or unsubstituted alkynyl radical, a substitutedor unsubstituted aralkyl radical, a substituted or unsubstituted arylradical or a substituted or unsubstituted heterocyclic radical, it beingpossible for the pairs R⁸⁷ and R⁶⁸, R⁶⁷ and R⁶⁵, R⁶⁸ and R⁶⁶, and R⁶⁵and R⁶⁶ to be connected to form a ring, and s and t are eachindependently of the other 0 or an integer from 1 to 4, provided thatwhen s and t have a value of 2 or more the groups R⁶⁷ and R⁶⁸ may be thesame or different.
 18. An oxonol dye according to the following generalformula:

wherein M^(k+) is an ammonium cation, k is an integer from 1 to 4, R⁴¹and R^(41′) are each independently of the other a hydrogen atom, aC₁₋₄alkyl radical, a perfluoro-C₁₋₄alkyl radical, a hydroxy-C₁₋₄alkylradical, a C₁₋₈alkyl radical interrupted one or more times by —O—, aC₆₋₁₀aryl radical, or a C₇₋₁₂aralkyl radical, R⁴² and R^(42′) are eachindependently of the other a hydrogen atom, a cyano or carboxamidegroup, R⁴³ and R^(43′) are each independently of the other a hydrogenatom, a carboxylic acid group or a salt thereof or a C₁₋₄alkyl radical,R⁴⁴ and R^(44′) are each independently of the other a hydrogen atom, aC₁₋₄alkyl radical, a C₆₋₁₂aryl or C₇₋₁₂aralkyl radical, or R⁴⁴ andR^(44′) together form a five-membered or six-membered ring, and R⁴⁵ is ahydrogen atom, a halogen atom, an unsubstituted or C₁₋₄alkyl- orC₁₋₄alkoxy-substituted C₆₋₁₂aryl radical, or a C₇₋₁₂aralkyl radical. 19.An oxonol dye according to claim 18, wherein M^(k+) is an ammoniumcation selected from the group consisting of K-1, K-2, K-3, K-4, M-1,M-2, M-3 and M-4, k is an integer from 1 to 2, R⁴¹ and R⁴¹ are eachindependently selected from the group consisting of methyl, ethyl,trifluoromethyl, CH₂CH₂CH₂—O—CH(CH₃)₂, phenyl, and benzyl.
 20. An oxonoldye according to claim 18, wherein M^(k+), R⁴¹ and R^(41′) have thefollowing meaning: Compound R⁴¹ = R^(41′) (1/k) M^(K+) D-1CH₂CH₂CH₂—O—CH(CH₃)₂ K-1 D-2 CH₂CH₂CH₂—O—CH(CH₃)₂ K-2 D-4 CH₃ K-1 D-5CH₃ K-2 D-6 C₂H₅ K-1 D-7 C₂H₅ K-2 D-8 CH₂CH₂CH₂—O—CH(CH₃)₂ M-1 D-9CH₂CH₂CH₂—O—CH(CH₃)₂ M-2 D-10 CH₂CH₂CH₂—O—CH(CH₃)₂ M-3 D-11CH₂CH₂CH₂—O—CH(CH₃)₂ M-4 D-12 phenyl K-2 D-14 CH₂CH₂CH₂—O—CH(CH₃)₂ K-3D-15 CH₂CH₂CH₂—O—CH(CH₃)₂ K-2 D-16 CH₂CH₂CH₂—O—CH(CH₃)₂ K-1 D-17CH₂CH₂CH₂—O—CH(CH₃)₂ K-4 D-49 C₂H₅ K-3 and Compound R⁴¹ R^(41′) (1/k)M^(K+) D-20 CH₃ C₂H₅ K-2 D-7 C₂H₅ C₂H₅ K-2 D-5 CH₃ CH₃ K-2 D-21 phenylC₂H₅ K-2 D-12 phenyl phenyl K-2 D-22 phenyl CH₂CH₂ CH₂—O—CH(CH₃)₂ K-2D-15 CH₂CH₂ CH₂—O—CH(CH₃)₂ CH₂CH₂ CH₂—O—CH(CH₃)₂ K-2 D-23 C₂H₅ CH₂CH₂CH₂—O—CH(CH₃)₂ K-2